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Alzheimer’s Disease and Toxins Produced by Marine Dinoflagellates: An Issue to Explore. Mar Drugs 2022; 20:md20040253. [PMID: 35447926 PMCID: PMC9029327 DOI: 10.3390/md20040253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 12/10/2022] Open
Abstract
This paper examined the toxins naturally produced by marine dinoflagellates and their effects on increases in β-amyloid plaques along with tau protein hyperphosphorylation, both major drivers of Alzheimer’s disease (AD). This approach is in line with the demand for certain natural compounds, namely those produced by marine invertebrates that have the potential to be used in the treatment of AD. Current advances in AD treatment are discussed as well as the main factors that potentially affect the puzzling global AD pattern. This study focused on yessotoxins (YTXs), gymnodimine (GYM), spirolides (SPXs), and gambierol, all toxins that have been shown to reduce β-amyloid plaques and tau hyperphosphorylation, thus preventing the neuronal or synaptic dysfunction that ultimately causes the cell death associated with AD (or other neurodegenerative diseases). Another group of toxins described, okadaic acid (OA) and its derivatives, inhibit protein phosphatase activity, which facilitates the presence of phosphorylated tau proteins. A few studies have used OA to trigger AD in zebrafish, providing an opportunity to test in vivo the effectiveness of new drugs in treating or attenuating AD. Constraints on the production of marine toxins for use in these tests have been considered. Different lines of research are anticipated regarding the action of the two groups of toxins.
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Sasaki M, Iwasaki K, Arai K, Hamada N, Umehara A. Convergent Synthesis of the HIJKLMN-Ring Fragment of Caribbean Ciguatoxin C-CTX-1 by a Late-Stage Reductive Olefin Coupling Approach. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2022. [DOI: 10.1246/bcsj.20220070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577
| | - Kotaro Iwasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577
| | - Keisuke Arai
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577
| | - Naoya Hamada
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577
| | - Atsushi Umehara
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577
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3
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Sakai T, Mizuno S, Sone A, Hori Y, Yamazaki W, Takazawa K, Mori Y. Biomimetic Construction of a syn-2,7-Dimethyloxepane Ring via 7- Endo Cyclization. J Org Chem 2021; 87:579-594. [PMID: 34958571 DOI: 10.1021/acs.joc.1c02600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
syn-2,7-Dimethyloxepane is a unique structure observed in natural ladder-shaped polycyclic ethers (LSPs), such as Caribbean ciguatoxins, gymnocin-B, and brevisulcenal-F that exhibit potent biological activities. Thus, the successful construction of this seven-membered ring is desirable, but its ring strain and the 1,3-repulsion between its two methyl groups makes this process difficult. Herein, we prepared syn-2,7-dimethyloxepanes via 7-endo cyclizations of vinyl epoxides that break Baldwin's rules. Such a biomimetic approach to syn-2,7-dimethyloxepanes has not yet been reported; however, we achieved this challenging cyclization with the aid of a cis-olefin tether and an unsubstituted vinyl group. The NO-ring fragment of gymnocin-B was also prepared from one of these 7-endo cyclized products, demonstrating the potential application of this strategy in constructing bioactive LSPs.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Sae Mizuno
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Akitaka Sone
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yasuko Hori
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Wakana Yamazaki
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Keisuke Takazawa
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yuji Mori
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
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4
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Fuwa H. Synthesis-Driven Stereochemical Assignment of Marine Polycyclic Ether Natural Products. Mar Drugs 2021; 19:257. [PMID: 33947080 PMCID: PMC8145320 DOI: 10.3390/md19050257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 01/11/2023] Open
Abstract
Marine polycyclic ether natural products have gained significant interest from the chemical community due to their impressively huge molecular architecture and diverse biological functions. The structure assignment of this class of extraordinarily complex natural products has mainly relied on NMR spectroscopic analysis. However, NMR spectroscopic analysis has its own limitations, including configurational assignment of stereogenic centers within conformationally flexible systems. Chemical shift deviation analysis of synthetic model compounds is a reliable means to assign the relative configuration of "difficult" stereogenic centers. The complete configurational assignment must be ultimately established through total synthesis. The aim of this review is to summarize the indispensable role of organic synthesis in stereochemical assignment of marine polycyclic ethers.
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Affiliation(s)
- Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo 112-8551, Japan
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Loeffler CR, Tartaglione L, Friedemann M, Spielmeyer A, Kappenstein O, Bodi D. Ciguatera Mini Review: 21st Century Environmental Challenges and the Interdisciplinary Research Efforts Rising to Meet Them. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:3027. [PMID: 33804281 PMCID: PMC7999458 DOI: 10.3390/ijerph18063027] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 03/12/2021] [Accepted: 03/12/2021] [Indexed: 12/19/2022]
Abstract
Globally, the livelihoods of over a billion people are affected by changes to marine ecosystems, both structurally and systematically. Resources and ecosystem services, provided by the marine environment, contribute nutrition, income, and health benefits for communities. One threat to these securities is ciguatera poisoning; worldwide, the most commonly reported non-bacterial seafood-related illness. Ciguatera is caused by the consumption of (primarily) finfish contaminated with ciguatoxins, potent neurotoxins produced by benthic single-cell microalgae. When consumed, ciguatoxins are biotransformed and can bioaccumulate throughout the food-web via complex pathways. Ciguatera-derived food insecurity is particularly extreme for small island-nations, where fear of intoxication can lead to fishing restrictions by region, species, or size. Exacerbating these complexities are anthropogenic or natural changes occurring in global marine habitats, e.g., climate change, greenhouse-gas induced physical oceanic changes, overfishing, invasive species, and even the international seafood trade. Here we provide an overview of the challenges and opportunities of the 21st century regarding the many facets of ciguatera, including the complex nature of this illness, the biological/environmental factors affecting the causative organisms, their toxins, vectors, detection methods, human-health oriented responses, and ultimately an outlook towards the future. Ciguatera research efforts face many social and environmental challenges this century. However, several future-oriented goals are within reach, including digital solutions for seafood supply chains, identifying novel compounds and methods with the potential for advanced diagnostics, treatments, and prediction capabilities. The advances described herein provide confidence that the tools are now available to answer many of the remaining questions surrounding ciguatera and therefore protection measures can become more accurate and routine.
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Affiliation(s)
- Christopher R. Loeffler
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
- Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy;
| | - Luciana Tartaglione
- Department of Pharmacy, School of Medicine and Surgery, University of Napoli Federico II, Via D. Montesano 49, 80131 Napoli, Italy;
- CoNISMa—National Inter-University Consortium for Marine Sciences, Piazzale Flaminio 9, 00196 Rome, Italy
| | - Miriam Friedemann
- Department Exposure, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany;
| | - Astrid Spielmeyer
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
| | - Oliver Kappenstein
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
| | - Dorina Bodi
- National Reference Laboratory of Marine Biotoxins, Department Safety in the Food Chain, German Federal Institute for Risk Assessment, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany; (A.S.); (O.K.); (D.B.)
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6
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Fuwa H. Structure determination, correction, and disproof of marine macrolide natural products by chemical synthesis. Org Chem Front 2021. [DOI: 10.1039/d1qo00481f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Integration of chemical synthesis, NMR spectroscopy, and various analytical means is key to success in the structure elucidation of stereochemically complex marine macrolide natural products.
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Affiliation(s)
- Haruhiko Fuwa
- Department of Applied Chemistry
- Faculty of Science and Engineering
- Chuo University
- Tokyo 112-8551
- Japan
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7
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Kato S, Mizukami D, Sugai T, Tsuda M, Fuwa H. Total synthesis and complete configurational assignment of amphirionin-2. Chem Sci 2020; 12:872-879. [PMID: 34163854 PMCID: PMC8179035 DOI: 10.1039/d0sc06021f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Amphirionin-2 is a linear polyketide metabolite that exhibits potent and selective cytotoxic activity against certain human cancer cell lines. We disclose herein the first total synthesis of amphirionin-2 and determination of its absolute configuration. Our synthesis featured an extensive use of cobalt-catalyzed Mukaiyama-type cyclization of γ-hydroxy olefins for stereoselective formation of all the tetrahydrofuran rings found in the natural product, and a late-stage Stille-type coupling for convergent assembly of the entire carbon backbone. Four candidate diastereomers of amphirionin-2 were synthesized in a unified, convergent manner, and their spectroscopic/chromatographic properties were compared with those of the authentic material. The present study culminated in the reassignment of the C5/C7 relative configuration, assignment of the C12/C18 relative configuration, and determination of the absolute configuration of amphirionin-2. An extensive application of cobalt-catalyzed Mukaiyama-type cyclization of γ-hydroxy olefins and a late-stage Stille-type reaction enabled syntheses of four diastereomers of amphirionin-2 to establish its absolute configuration.![]()
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Affiliation(s)
- Shota Kato
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Daichi Mizukami
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Tomoya Sugai
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Masashi Tsuda
- Center for Advanced Marine Core Research and Department of Agriculture and Marine Science, Kochi University Nankoku Kochi 783-8502 Japan
| | - Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
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Čubiňák M, Tobrman T. Room-Temperature Negishi Reaction of Trisubstituted Vinyl Phosphates for the Synthesis of Tetrasubstituted Alkenes. J Org Chem 2020; 85:10728-10739. [PMID: 32674569 DOI: 10.1021/acs.joc.0c01254] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The present study investigated the ability of bromovinyl phosphates to react with organozinc reagents at room temperature during palladium-catalyzed reactions. It was determined that both the bromine atom and the phosphate group were successfully substituted by means of the reaction with the organozinc reagents, thereby allowing for the synthesis of cyclic and acyclic tetrasubstituted double bonds. The low stability of the organozinc compounds in an acidic environment was exploited to accomplish the synthesis of alkenes using a one-pot, two-step experimental setup.
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Affiliation(s)
- Marek Čubiňák
- Department of Organic Chemistry, University of Chemistry and Technology, Technická 5, 166 28 Prague 6, Czech Republic
| | - Tomáš Tobrman
- Department of Organic Chemistry, University of Chemistry and Technology, Technická 5, 166 28 Prague 6, Czech Republic
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10
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Satake M, Yasumoto T. Methods for determining the absolute configurations of marine ladder‐shaped polyethers. Chirality 2020; 32:474-483. [DOI: 10.1002/chir.23187] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Masayuki Satake
- Department of Chemistry, School of ScienceThe University of Tokyo Tokyo Japan
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11
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12
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Sakai T, Sakakibara H, Omoto Y, Tsunekawa M, Hadano Y, Kato S, Mori Y. Synthesis of the GHIJKL Fragment of Gymnocin-B. Org Lett 2019; 21:6864-6868. [PMID: 31436430 DOI: 10.1021/acs.orglett.9b02502] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The GHIJKL fragment of gymnocin-B was synthesized using the oxiranyl anion strategy. The first highlight of the synthesis is the bromoketone cyclization reaction on the oxepane ring to construct the fused bisoxepane GH ring. The second key step is the introduction of the trans-4-hydroxy-3-methyloxepane J ring via addition of trimethylaluminum to a conjugated oxonium moiety, followed by diastereoselective epoxidation and regioselective reduction.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Hideaki Sakakibara
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yumi Omoto
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Marina Tsunekawa
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yoshinori Hadano
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Shota Kato
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yuji Mori
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
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13
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Elustondo F, Chintalapudi V, Clark JS. A Short Sequence for the Iterative Synthesis of Fused Polyethers. Helv Chim Acta 2019. [DOI: 10.1002/hlca.201900161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Frédéric Elustondo
- School of ChemistryUniversity of Nottingham, University Park Nottingham NG7 2RD United Kingdom
| | - Venkaiah Chintalapudi
- School of Chemistry, Joseph Black BuildingUniversity of Glasgow, University Avenue Glasgow G12 8QQ United Kingdom
| | - J. Stephen Clark
- School of Chemistry, Joseph Black BuildingUniversity of Glasgow, University Avenue Glasgow G12 8QQ United Kingdom
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Sakamoto K, Fuwa H. Total Synthesis of a Marine Macrolide Natural Product, Iriomoteolide-2a: The Fundamental Role of Total Synthesis in Natural Product Chemistry. J SYN ORG CHEM JPN 2019. [DOI: 10.5059/yukigoseikyokaishi.77.831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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15
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Sakamoto K, Hakamata A, Iwasaki A, Suenaga K, Tsuda M, Fuwa H. Total Synthesis, Stereochemical Revision, and Biological Assessment of Iriomoteolide-2a. Chemistry 2019; 25:8528-8542. [PMID: 30882926 DOI: 10.1002/chem.201900813] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/13/2019] [Indexed: 01/14/2023]
Abstract
Iriomoteolide-2a is a marine macrolide metabolite isolated from a cultured broth of the benthic dinoflagellate Amphidinium sp. HYA024 strain. This naturally occurring substance was reported to show remarkable cytotoxic activity against human cancer cell lines HeLa and DG-75 and in vivo antitumor activity against murine leukemia P388 cell line. Herein, the total synthesis, stereochemical revision, and biological assessment of iriomoteolide-2a are reported in detail. Total synthesis of the proposed structure 1 of iriomoteolide-2a featured a late-stage convergent assembly of three components by a Suzuki-Miyaura coupling, an esterification, and a ring-closing metathesis. However, the NMR data of synthetic 1 were not identical to those of the natural product. Careful analysis of the NMR data of the authentic material and synthesis/NMR analysis of appropriately designed model compounds led to consideration of four possible stereoisomers 2-5 as candidates for the correct structure. Accordingly, total syntheses of 2-5 were achieved by taking advantage of the convergent strategy, and comparison of the NMR spectra of synthetic 2-5 with those of the natural product led to the conclusion that 5 shows the correct relative configuration of iriomoteolide-2a. The absolute configuration of this natural product was finally established through chiral HPLC analysis of synthetic 5/ent-5 with the authentic sample. The antiproliferative activity of the synthetic compounds was assessed against HeLa and A549 cells to show that, in contrast to expectation, synthetic 5 and ent-5 were only marginally active in these cell lines. This work clearly underscores the vital role of total synthesis in the establishment of the structure and biological activity of natural products.
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Affiliation(s)
- Keita Sakamoto
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.,Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Akihiro Hakamata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Arihiro Iwasaki
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Kiyotake Suenaga
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Masashi Tsuda
- Center for Advanced Marine Core Research and Department of, Agriculture and Marine Science, Kochi University, Nankoku, Kochi, 783-8502, Japan
| | - Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan
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Oishi T. Design and Synthesis of Artificial Ladder-Shaped Polyethers for Exploring Biological Functions. HETEROCYCLES 2019. [DOI: 10.3987/rev-18-sr(f)1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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17
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Sakamoto K, Hakamata A, Tsuda M, Fuwa H. Total Synthesis and Stereochemical Revision of Iriomoteolide-2a. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800507] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Keita Sakamoto
- Department of Applied Chemistry; Faculty of Science and Engineering; Chuo University, 1-13-27 Kasuga; Bunkyo-ku Tokyo 112-8551 Japan
- Graduate School of Life Sciences; Tohoku University; 2-1-1 Katahira Aoba-ku Sendai 980-8577 Japan
| | - Akihiro Hakamata
- Graduate School of Life Sciences; Tohoku University; 2-1-1 Katahira Aoba-ku Sendai 980-8577 Japan
| | - Masashi Tsuda
- Center for Advanced Marine Core Research and Department of Agriculture and Marine Science; Kochi University; Nankoku Kochi 783-8502 Japan
| | - Haruhiko Fuwa
- Department of Applied Chemistry; Faculty of Science and Engineering; Chuo University, 1-13-27 Kasuga; Bunkyo-ku Tokyo 112-8551 Japan
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18
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Sakamoto K, Hakamata A, Tsuda M, Fuwa H. Total Synthesis and Stereochemical Revision of Iriomoteolide-2a. Angew Chem Int Ed Engl 2018; 57:3801-3805. [PMID: 29385300 DOI: 10.1002/anie.201800507] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Indexed: 12/16/2022]
Abstract
Total syntheses of the proposed and correct structures of iriomoteolide-2a, a cytotoxic marine macrolide natural product with an unusual 23-membered macrolactone skeleton, have been accomplished for the first time. The synthesis of the correct structure involves an asymmetric epoxidation/diepoxide cyclization cascade for the construction of the bis(tetrahydrofuran) moiety, a Suzuki-Miyaura coupling for the fragment assembly, and a ring-closing metathesis for the closure of the macrocyclic backbone. In addition, the original stereochemical assignment of iriomoteolide-2a was revised.
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Affiliation(s)
- Keita Sakamoto
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.,Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Akihiro Hakamata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Masashi Tsuda
- Center for Advanced Marine Core Research and Department of Agriculture and Marine Science, Kochi University, Nankoku, Kochi, 783-8502, Japan
| | - Haruhiko Fuwa
- Department of Applied Chemistry, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan
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Mori Y, Sakai T, Aoyama K, Oshima R, Furukawa K. Stereoinversion of a Tertiary Alcohol on a THP Ring: a Recovery Route to an Intermediate for Gymnocin-A. HETEROCYCLES 2018. [DOI: 10.3987/com-17-s(t)8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Assunção J, Guedes AC, Malcata FX. Biotechnological and Pharmacological Applications of Biotoxins and Other Bioactive Molecules from Dinoflagellates. Mar Drugs 2017; 15:E393. [PMID: 29261163 PMCID: PMC5742853 DOI: 10.3390/md15120393] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 12/26/2022] Open
Abstract
The long-lasting interest in bioactive molecules (namely toxins) produced by (microalga) dinoflagellates has risen in recent years. Exhibiting wide diversity and complexity, said compounds are well-recognized for their biological features, with great potential for use as pharmaceutical therapies and biological research probes. Unfortunately, provision of those compounds is still far from sufficient, especially in view of an increasing demand for preclinical testing. Despite the difficulties to establish dinoflagellate cultures and obtain reasonable productivities of such compounds, intensive research has permitted a number of advances in the field. This paper accordingly reviews the characteristics of some of the most important biotoxins (and other bioactive substances) produced by dinoflagellates. It also presents and discusses (to some length) the main advances pertaining to dinoflagellate production, from bench to large scale-with an emphasis on material published since the latest review available on the subject. Such advances encompass improvements in nutrient formulation and light supply as major operational conditions; they have permitted adaptation of classical designs, and aided the development of novel configurations for dinoflagellate growth-even though shearing-related issues remain a major challenge.
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Affiliation(s)
- Joana Assunção
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
| | - A Catarina Guedes
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, s/n, P-4450-208 Matosinhos, Portugal.
| | - F Xavier Malcata
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
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21
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Diogène J, Reverté L, Rambla-Alegre M, Del Río V, de la Iglesia P, Campàs M, Palacios O, Flores C, Caixach J, Ralijaona C, Razanajatovo I, Pirog A, Magalon H, Arnich N, Turquet J. Identification of ciguatoxins in a shark involved in a fatal food poisoning in the Indian Ocean. Sci Rep 2017; 7:8240. [PMID: 28811602 PMCID: PMC5557899 DOI: 10.1038/s41598-017-08682-8] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/20/2017] [Indexed: 11/09/2022] Open
Abstract
Severe food poisoning events after the consumption of sharks have been reported since the 1940s; however, there has been no clear understanding of their cause. Herein, we report for the first time the presence of ciguatoxins (CTXs) in sharks. The identification by mass spectrometry of CTXs, including two new analogues, in a bull shark (Carcharhinus leucas) that was consumed by humans, causing the poisoning and death of 11 people in Madagascar in 2013 is described. Typical neurotoxic ciguatera symptoms were recorded in patients, and toxicological assays on extracts of the shark demonstrated CTX-like activity. These results confirm this episode as a ciguatera poisoning event and expand the range of pelagic fish species that are involved in ciguatera in the Indian Ocean. Additionally, gambieric acid D, a molecule originally described in CTX-producing microalgae, was identified for the first time in fish. This finding can contribute to a better understanding of trophic relations within food webs. The present work confirms that consumption of sharks from the Indian Ocean should be considered a ciguatera risk, and actions should be taken to evaluate its magnitude and risk in order to manage shark fisheries.
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Affiliation(s)
- Jorge Diogène
- Marine Environmental Monitoring, IRTA, Ctra. Poble Nou, km 5.5, 43540, Sant Carles de la, Ràpita, Spain.
| | - Laia Reverté
- Marine Environmental Monitoring, IRTA, Ctra. Poble Nou, km 5.5, 43540, Sant Carles de la, Ràpita, Spain
| | - Maria Rambla-Alegre
- Marine Environmental Monitoring, IRTA, Ctra. Poble Nou, km 5.5, 43540, Sant Carles de la, Ràpita, Spain
| | - Vanessa Del Río
- Marine Environmental Monitoring, IRTA, Ctra. Poble Nou, km 5.5, 43540, Sant Carles de la, Ràpita, Spain
| | - Pablo de la Iglesia
- Marine Environmental Monitoring, IRTA, Ctra. Poble Nou, km 5.5, 43540, Sant Carles de la, Ràpita, Spain
| | - Mònica Campàs
- Marine Environmental Monitoring, IRTA, Ctra. Poble Nou, km 5.5, 43540, Sant Carles de la, Ràpita, Spain
| | - Oscar Palacios
- Mass Spectrometry Laboratory/Organic Pollutants, IDAEA-CSIC, Jordi Girona 18, 08034, Barcelona, Spain
| | - Cintia Flores
- Mass Spectrometry Laboratory/Organic Pollutants, IDAEA-CSIC, Jordi Girona 18, 08034, Barcelona, Spain
| | - Josep Caixach
- Mass Spectrometry Laboratory/Organic Pollutants, IDAEA-CSIC, Jordi Girona 18, 08034, Barcelona, Spain
| | - Christian Ralijaona
- IHSM, Institut Halieutique des Sciences Marines de Tuléar, Université de Toliara, Toliara, Madagascar
| | - Iony Razanajatovo
- IPM Institut Pasteur Madagascar, Laboratoire d'Epidémio-Surveillance, BP 1274 - Avaradoha, 101, Antananarivo, Madagascar
| | - Agathe Pirog
- UMR ENTROPIE Univ. Réunion/IRD/CNRS, Faculté des Sciences et Technologies, Université de La Réunion, 15 Bd René Cassin, CS 92003, 97744 St Denis Cedex 09, La Réunion, France
| | - Hélène Magalon
- UMR ENTROPIE Univ. Réunion/IRD/CNRS, Faculté des Sciences et Technologies, Université de La Réunion, 15 Bd René Cassin, CS 92003, 97744 St Denis Cedex 09, La Réunion, France
| | - Nathalie Arnich
- ANSES French Agency for Food, Environmental and Occupational Health & Safety, Unit on Food Risk Assessment, Risk Assessment Department, 14 rue Pierre et Marie Curie - 94701, Maisons-Alfort Cedex, France
| | - Jean Turquet
- HYDROREUNION, CBEM, C/O CYROI, 2, Rue Maxime Rivière, 97490, Sainte Clotilde, La Réunion, France
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22
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Sakai T, Ishihara A, Mori Y. Synthesis of the KLMN Fragment of Gymnocin-A from the FGH Fragment. J Org Chem 2017; 82:3976-3981. [PMID: 28276689 DOI: 10.1021/acs.joc.7b00232] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An improved route for the synthesis of the KLMN fragment of gymnocin-A was developed through the oxiranyl anion coupling of the FGH fragment with a chiral C3 epoxy sulfone, followed by 6-endo cyclization. This straightforward approach reduced the number of synthetic steps by 14 compared with a previous route using alternative building blocks.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Aoi Ishihara
- Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yuji Mori
- Faculty of Pharmacy, Meijo University , 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
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23
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Fuwa H, Sasaki M. Exploiting Ruthenium Carbene-Catalyzed Reactions in Total Synthesis of Marine Oxacyclic Natural Products. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2016. [DOI: 10.1246/bcsj.20160224] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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24
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Onodera Y, Hirota K, Suga Y, Konoki K, Yotsu-Yamashita M, Sasaki M, Fuwa H. Diastereoselective Ring-Closing Metathesis as a Means to Construct Medium-Sized Cyclic Ethers: Application to the Synthesis of a Photoactivatable Gambierol Derivative. J Org Chem 2016; 81:8234-52. [DOI: 10.1021/acs.joc.6b01302] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yu Onodera
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Kazuaki Hirota
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Yuto Suga
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Keiichi Konoki
- Graduate
School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
| | - Mari Yotsu-Yamashita
- Graduate
School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-amamiyamachi, Aoba-ku, Sendai 981-8555, Japan
| | - Makoto Sasaki
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
| | - Haruhiko Fuwa
- Graduate
School of Life Sciences, Tohoku University, 2-1-1 Katahira,
Aoba-ku, Sendai 980-8577, Japan
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25
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de la Torre A, Cuyamendous C, Bultel-Poncé V, Durand T, Galano JM, Oger C. Recent advances in the synthesis of tetrahydrofurans and applications in total synthesis. Tetrahedron 2016. [DOI: 10.1016/j.tet.2016.06.076] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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26
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Kawashima Y, Toyoshima A, Fuwa H, Sasaki M. Toward the Total Synthesis of Amphidinolide N: Synthesis of the C8–C29 Fragment. Org Lett 2016; 18:2232-5. [DOI: 10.1021/acs.orglett.6b00871] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yuki Kawashima
- Graduate School of Life Sciences, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Atsushi Toyoshima
- Graduate School of Life Sciences, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Haruhiko Fuwa
- Graduate School of Life Sciences, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai 980-8577, Japan
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27
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Fuwa H, Yamagata N, Okuaki Y, Ogata Y, Saito A, Sasaki M. Total Synthesis and Complete Stereostructure of a Marine Macrolide Glycoside, (-)-Lyngbyaloside B. Chemistry 2016; 22:6815-29. [PMID: 27112323 DOI: 10.1002/chem.201600341] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Indexed: 11/05/2022]
Abstract
We have described in detail the total synthesis of both the proposed and correct structures of (-)-lyngbyaloside B, which facilitated the elucidation of the complete stereostructure of this natural product. Our study began with the total synthesis of 13-demethyllyngbyaloside B, in which an esterification/ring-closing metathesis (RCM) strategy was successfully used for the efficient construction of the macrocycle. We also established reliable methods for the introduction of the conjugated diene side chain and the l-rhamnose residue onto the macrocyclic framework. However, the esterification/RCM strategy proved ineffective for the parent natural product because of the difficulties in acylating the sterically encumbered C-13 tertiary alcohol; macrolactionization of a seco-acid was also extensively investigated under various conditions without success. We finally completed the total synthesis of the proposed structure of (-)-lyngbyaloside B by means of a macrolactonization that involves an acyl ketene as the reactive species. However, the NMR spectroscopic data of our synthetic material did not match those of the authentic material, which indicated that the proposed structure must be re-examined. Inspection of the NMR spectroscopic data of the natural product and molecular mechanics calculations led us to postulate that the configuration of the C-10, C-11, and C-13 stereogenic centers had been incorrectly assigned in the proposed structure. Finally, our revised structure of (-)-lyngbyaloside B was unambiguously verified through total synthesis.
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Affiliation(s)
- Haruhiko Fuwa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Naoya Yamagata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Yuta Okuaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Yuya Ogata
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Asami Saito
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
| | - Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
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28
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Fuwa H. Contemporary Strategies for the Synthesis of Tetrahydropyran Derivatives: Application to Total Synthesis of Neopeltolide, a Marine Macrolide Natural Product. Mar Drugs 2016; 14:E65. [PMID: 27023567 PMCID: PMC4849069 DOI: 10.3390/md14040065] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 03/15/2016] [Accepted: 03/17/2016] [Indexed: 02/07/2023] Open
Abstract
Tetrahydropyrans are structural motifs that are abundantly present in a range of biologically important marine natural products. As such, significant efforts have been paid to the development of efficient and versatile methods for the synthesis of tetrahydropyran derivatives. Neopeltolide, a potent antiproliferative marine natural product, has been an attractive target compound for synthetic chemists because of its complex structure comprised of a 14-membered macrolactone embedded with a tetrahydropyran ring, and twenty total and formal syntheses of this natural product have been reported so far. This review summarizes the total and formal syntheses of neopeltolide and its analogues, highlighting the synthetic strategies exploited for constructing the tetrahydropyran ring.
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Affiliation(s)
- Haruhiko Fuwa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan.
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29
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Beaver MG, Buscagan TM, Lavinda O, Woerpel KA. Stereoelectronic Model To Explain Highly Stereoselective Reactions of Seven-Membered-Ring Oxocarbenium-Ion Intermediates. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201507806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Trixia M. Buscagan
- Department of Chemistry and Chemical Engineering; California Institute of Technology; 1200 E. California Blvd, MNC 101-20 Pasadena CA 91125 USA
| | - Olga Lavinda
- Department of Chemistry; New York University; 100 Washington Square East New York NY 10003 USA
| | - K. A. Woerpel
- Department of Chemistry; New York University; 100 Washington Square East New York NY 10003 USA
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30
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Beaver MG, Buscagan TM, Lavinda O, Woerpel KA. Stereoelectronic Model To Explain Highly Stereoselective Reactions of Seven-Membered-Ring Oxocarbenium-Ion Intermediates. Angew Chem Int Ed Engl 2016; 55:1816-9. [PMID: 26791884 DOI: 10.1002/anie.201507806] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 10/20/2015] [Indexed: 11/11/2022]
Abstract
Nucleophilic attack on seven-membered-ring oxocarbenium ions is generally highly stereoselective. The preferred mode of nucleophilic attack forms the product in a conformation that minimizes transannular interactions, thus leading to different stereoselectivity as compared to that of reactions involving six-membered-ring oxocarbenium ions.
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Affiliation(s)
| | - Trixia M Buscagan
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, MNC 101-20, Pasadena, CA, 91125, USA
| | - Olga Lavinda
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, USA
| | - K A Woerpel
- Department of Chemistry, New York University, 100 Washington Square East, New York, NY, 10003, USA.
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31
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Sakai T, Matsushita S, Arakawa S, Mori K, Tanimoto M, Tokumasu A, Yoshida T, Mori Y. Total Synthesis of Gymnocin-A. J Am Chem Soc 2015; 137:14513-6. [PMID: 26521846 DOI: 10.1021/jacs.5b10082] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A convergent total synthesis of cytotoxic marine natural polycyclic ether, gymnocin-A (1), is described. The synthesis features three iterations of an oxiranyl anion strategy, involving base-mediated cycloetherification, ring expansion, and reductive etherification, for the construction of the FGH fragment and for its coupling with the ABC and KLMN fragments.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Shingo Matsushita
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Shogo Arakawa
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Koichi Mori
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Miki Tanimoto
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Akihiro Tokumasu
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Tatsuji Yoshida
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yuji Mori
- Faculty of Pharmacy, Meijo University , Yagotoyama 150, Tempaku-ku, Nagoya 468-8503, Japan
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32
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Clark JS, Romiti F, Sieng B, Paterson LC, Stewart A, Chaudhury S, Thomas LH. Synthesis of the A–D Ring System of the Gambieric Acids. Org Lett 2015; 17:4694-7. [PMID: 26367818 DOI: 10.1021/acs.orglett.5b02093] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Stephen Clark
- WestCHEM,
School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Filippo Romiti
- WestCHEM,
School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Bora Sieng
- WestCHEM,
School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Laura C. Paterson
- WestCHEM,
School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Alister Stewart
- School
of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
| | - Subhabrata Chaudhury
- WestCHEM,
School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Lynne H. Thomas
- WestCHEM,
School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
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33
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Misassigned natural products and their revised structures. Arch Pharm Res 2015; 39:143-153. [DOI: 10.1007/s12272-015-0649-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 08/08/2015] [Indexed: 01/16/2023]
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34
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Fuwa H, Fukazawa R, Sasaki M. Concise synthesis of the A/BCD-ring fragment of gambieric acid A. Front Chem 2015; 2:116. [PMID: 25629027 PMCID: PMC4292782 DOI: 10.3389/fchem.2014.00116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/18/2014] [Indexed: 11/17/2022] Open
Abstract
Gambieric acid A (GAA) and its congeners belong to the family of marine polycyclic ether natural products. Their highly complex molecular architecture and unique biological activities have been of intense interest within the synthetic community. We have previously reported the first total synthesis, stereochemical reassignment, and preliminary structure–activity relationships of GAA. Here we disclose a concise synthesis of the A/BCD-ring fragment of GAA. The synthesis started from our previously reported synthetic intermediate that represents the A/B-ring. The C-ring was synthesized via an oxiranyl anion coupling and a 6-endo cyclization, and the D-ring was forged by means of an oxidative lactonization and subsequent palladium-catalyzed functionalization of the lactone ring. In this manner, the number of linear synthetic steps required for the construction of the C- and D-rings was reduced from 22 to 11.
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Affiliation(s)
- Haruhiko Fuwa
- Graduate School of Life Sciences, Tohoku University Sendai, Japan
| | - Ryo Fukazawa
- Graduate School of Life Sciences, Tohoku University Sendai, Japan
| | - Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University Sendai, Japan
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35
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36
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Fuwa H, Okuaki Y, Yamagata N, Sasaki M. Total Synthesis, Stereochemical Reassignment, and Biological Evaluation of (−)-Lyngbyaloside B. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409629] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Fuwa H, Okuaki Y, Yamagata N, Sasaki M. Total synthesis, stereochemical reassignment, and biological evaluation of (-)-lyngbyaloside B. Angew Chem Int Ed Engl 2014; 54:868-73. [PMID: 25393532 DOI: 10.1002/anie.201409629] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Indexed: 11/09/2022]
Abstract
(-)-Lyngbyaloside B is a 14-membered macrolide glycoside isolated from the marine cyanobacterium Lyngbya sp. as a cytotoxic substance by Moore and co-workers. The first total synthesis of (-)-lyngbyaloside B and the reassignment of its stereostructure is described. The synthesis features an Abiko-Masamune aldol reaction, a vinylogous Mukaiyama aldol reaction, and a macrocyclization involving an acyl ketene intermediate for the construction of the macrocyclic backbone, which contains an acylated tertiary alcohol. The antiproliferative activity of selected compounds against a small panel of human cancer cell lines is also reported.
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Affiliation(s)
- Haruhiko Fuwa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan).
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38
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39
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Sasaki M, Fuwa H. Total synthesis and complete structural assignment of gambieric acid A, a large polycyclic ether marine natural product. CHEM REC 2014; 14:678-703. [PMID: 25092231 DOI: 10.1002/tcr.201402052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Indexed: 12/30/2022]
Abstract
More than thirty years after the discovery of polycyclic ether marine natural products, they continue to receive intense attention from the chemical, biological, and pharmacological communities because of their potent biological activities and highly complex molecular architectures. Gambieric acids are intriguing polycyclic ethers that exhibit potent antifungal activity with minimal toxicity against mammals. Despite the recent advances in the synthesis of this class of natural products, gambieric acids remain unconquered due to their daunting structural complexity, which poses a formidable synthetic challenge to organic chemists. This paper reviews our long-term studies on the total synthesis, complete configurational reassignment, and structure-activity relationships of gambieric acid A over the last decade.
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Affiliation(s)
- Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, Katahira, Aoba-ku, Sendai 980-8577, Japan.
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40
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Herndon JW. The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2012. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.02.026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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41
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Lanier ML, Kasper AC, Kim H, Hong J. Synthesis of α,α'-trans-oxepanes through an organocatalytic oxa-conjugate addition reaction. Org Lett 2014; 16:2406-9. [PMID: 24724535 PMCID: PMC4018174 DOI: 10.1021/ol500773w] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
![]()
Oxepanes
are found in a wide range of natural products; however,
they are challenging synthetic targets due to enthalpic and entropic
barriers. Organocatalytic oxa-conjugate addition reactions promoted
by the gem-disubstituent (Thorpe–Ingold) effect
stereoselectively provided α,α′-trans-oxepanes. In addition, the potential of an organocatalytic tandem
oxa-conjugate addition/α-oxidation was demonstrated in a rapid
generation of molecular complexity. These organocatalytic oxa-conjugate
addition reactions would provide powerful tools for the synthesis
of natural products that contain highly functionalized oxepanes.
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Affiliation(s)
- Megan L Lanier
- Department of Chemistry, Duke University , Durham, North Carolina 27708, United States
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42
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Sakai T, Asano H, Furukawa K, Oshima R, Mori Y. Synthesis of the KLMN Fragment of Gymnocin-A Using Oxiranyl Anion Convergent Methodology. Org Lett 2014; 16:2268-71. [DOI: 10.1021/ol500788c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Takeo Sakai
- Faculty
of Pharmacy, Meijo University, Yagotoyama
150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Haruka Asano
- Faculty
of Pharmacy, Meijo University, Yagotoyama
150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Kyoko Furukawa
- Faculty
of Pharmacy, Meijo University, Yagotoyama
150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Rie Oshima
- Faculty
of Pharmacy, Meijo University, Yagotoyama
150, Tempaku-ku, Nagoya 468-8503, Japan
| | - Yuji Mori
- Faculty
of Pharmacy, Meijo University, Yagotoyama
150, Tempaku-ku, Nagoya 468-8503, Japan
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Abstract
This review covers the literature published in 2012 for marine natural products, with 1035 citations (673 for the period January to December 2012) referring to compounds isolated from marine microorganisms and phytoplankton, green, brown and red algae, sponges, cnidarians, bryozoans, molluscs, tunicates, echinoderms, mangroves and other intertidal plants and microorganisms. The emphasis is on new compounds (1241 for 2012), together with the relevant biological activities, source organisms and country of origin. Biosynthetic studies, first syntheses, and syntheses that lead to the revision of structures or stereochemistries, have been included.
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Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
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Suga Y, Fuwa H, Sasaki M. Stereoselective Synthesis of Medium-Sized Cyclic Ethers: Application of C-Glycosylation Chemistry to Seven- to Nine-Membered Lactone-Derived Thioacetals and Their Sulfone Counterparts. J Org Chem 2014; 79:1656-82. [DOI: 10.1021/jo4025545] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Yuto Suga
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Haruhiko Fuwa
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Makoto Sasaki
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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45
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Domon D, Fujiwara K, Kawamura N, Katoono R, Kawai H, Suzuki T. A New Variant of Fused Cyclic Ether Synthesis Based on Ireland-Claisen Rearrangement and RCM. Nat Prod Commun 2013. [DOI: 10.1177/1934578x1300800718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
A new variant of fused cyclic ether synthesis based on Ireland-Claisen rearrangement and ring-closing olefin metathesis (RCM) was developed. The Ireland-Claisen rearrangement and ring-closing olefin metathesis (RCM) was developed. The Ireland-Claisen rearrangement of a ( Z)-3-alkoxyprop-2-en-1-yl glycolate ester having a cyclic ether on the oxygen at C3 of the ( Z)-prop-2-en-1-yl group stereoselectively produced an anti-α,β-dialkoxyester which was successfully transformed to a fused bicyclic ether via a reaction sequence including RCM.
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Affiliation(s)
- Daisuke Domon
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Kenshu Fujiwara
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Natsumi Kawamura
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Ryo Katoono
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Hidetoshi Kawai
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
| | - Takanori Suzuki
- Department of Chemistry Faculty of Science Hokkaido University Sapporo 606-0810 Japan
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46
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Ishigai K, Fuwa H, Hashizume K, Fukazawa R, Cho Y, Yotsu-Yamashita M, Sasaki M. Total synthesis and biological evaluation of (+)-gambieric acid A and its analogues. Chemistry 2013; 19:5276-88. [PMID: 23554126 DOI: 10.1002/chem.201204303] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 02/09/2013] [Indexed: 11/06/2022]
Abstract
In this study, we report the first total synthesis and complete stereostructure of gambieric acid A, a potent antifungal polycyclic ether metabolite, in detail. The A/B-ring exocyclic enol ether 32 was prepared through a Suzuki-Miyaura coupling of the B-ring vinyl iodide 18 and the alkylborate 33 and subsequent closure of the A-ring by using diastereoselective bromoetherification as the key transformation. Suzuki-Miyaura coupling of 32 with acetate-derived enol phosphate 49, followed by ring-closing metathesis of the derived diene, produced the D-ring. Subsequent closure of the C-ring through a mixed thioacetalization completed the synthesis of the A/BCD-ring fragment 8. The A/BCD- and F'GHIJ-ring fragments (i.e., 8 and 9) were assembled through Suzuki-Miyaura coupling. The C25 stereogenic center was elaborated by exploiting the intrinsic conformational property of the seven-membered F'-ring. After the oxidative cleavage of the F'-ring, the E-ring was formed as a cyclic mixed thioacetal (i.e., 70) and then stereoselectively allylated by using glycosylation chemistry. Ring-closing metathesis of the diene 3 thus obtained closed the F-ring and completed the polycyclic ether skeleton. Finally, the J-ring side chain was introduced by using a Julia-Kocienski olefination in the presence of CeCl3 to complete the total synthesis of gambieric acid A (1), thereby unambiguously establishing its complete stereostructure. The present total synthesis enabled us to evaluate the antifungal and antiproliferative activities of 1 and several synthetic analogues.
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Affiliation(s)
- Kazuya Ishigai
- Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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47
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48
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Sakai T, Sugimoto A, Tatematsu H, Mori Y. Divergent synthesis of trans-fused polycyclic ethers by a convergent oxiranyl anion strategy. J Org Chem 2012; 77:11177-91. [PMID: 23214941 DOI: 10.1021/jo302267f] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Octacyclic polyethers that correspond to the CDEFGHIJ-ring system of yessotoxin as well as G- and/or I-ring-modified analogues were synthesized in a divergent manner, starting from a common intermediate, using an [X + 2 + Y]-type convergent method. Reaction of a triflate with the oxiranyl anion generated from an epoxy sulfone, followed by ring expansion, allowed for the incorporation of medium-sized ring ethers into the key intermediate. Subsequent acetal formation and reductive etherification afforded various octacycles containing seven- and eight-membered ether rings.
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Affiliation(s)
- Takeo Sakai
- Faculty of Pharmacy, Meijo University, 150 Yagotoyama, Tempaku-ku, Nagoya 468-8503, Japan
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