1
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Holland DC, Prebble DW, Er S, Hayton JB, Robertson LP, Avery VM, Domanskyi A, Kiefel MJ, Hooper JNA, Carroll AR. α-Synuclein Aggregation Inhibitory Prunolides and a Dibrominated β-Carboline Sulfamate from the Ascidian Synoicum prunum. JOURNAL OF NATURAL PRODUCTS 2022; 85:441-452. [PMID: 35050597 DOI: 10.1021/acs.jnatprod.1c01172] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Seven new polyaromatic bis-spiroketal-containing butenolides, the prunolides D-I (4-9) and cis-prunolide C (10), a new dibrominated β-carboline sulfamate named pityriacitrin C (11), alongside the known prunolides A-C (1-3) were isolated from the Australian colonial ascidian Synoicum prunum. The prunolides D-G (4-7) represent the first asymmetrically brominated prunolides, while cis-prunolide C (10) is the first reported with a cis-configuration about the prunolide's bis-spiroketal core. The prunolides displayed binding activities with the Parkinson's disease-implicated amyloid protein α-synuclein in a mass spectrometry binding assay, while the prunolides (1-5 and 10) were found to significantly inhibit the aggregation (>89.0%) of α-synuclein in a ThT amyloid dye assay. The prunolides A-C (1-3) were also tested for inhibition of pSyn aggregate formation in a primary embryonic mouse midbrain dopamine neuron model with prunolide B (2) displaying statistically significant inhibitory activity at 0.5 μM. The antiplasmodial and antibacterial activities of the isolates were also examined with prunolide C (3) displaying only weak activity against the 3D7 parasite strain of Plasmodium falciparum. Our findings reported herein suggest that the prunolides could provide a novel scaffold for the exploration of future therapeutics aimed at inhibiting amyloid protein aggregation and the treatment of numerous neurodegenerative diseases.
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Affiliation(s)
- Darren C Holland
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Dale W Prebble
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Safak Er
- HiLIFE, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
- Faculty of Pharmacy, University of Helsinki, Helsinki 00014, Finland
| | - Joshua B Hayton
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Luke P Robertson
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
| | - Vicky M Avery
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
- Discovery Biology, Griffith University, Nathan, Queensland 4111, Australia
| | - Andrii Domanskyi
- HiLIFE, Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Milton J Kiefel
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Institute for Glycomics, Griffith University, Southport, Queensland 4221, Australia
| | - John N A Hooper
- Queensland Museum, South Brisbane BC, Queensland 4101, Australia
| | - Anthony R Carroll
- School of Environment and Science, Griffith University, Southport, Queensland 4222, Australia
- Griffith Institute for Drug Discovery, Griffith University, Nathan, Queensland 4111, Australia
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2
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Mandal S, Thirupathi B. Strategies for the construction of γ-spirocyclic butenolides in natural product synthesis. Org Biomol Chem 2021; 18:5287-5314. [PMID: 32633316 DOI: 10.1039/d0ob00954g] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the last four decades, a number of γ-spirocyclic butenolide containing natural products, drugs, and medicinally useful synthetic compounds have been reported. In this review, we discuss diverse chemical approaches to synthesize γ-spiro butenolides and their application towards natural product synthesis. The collective perception of various methods may allow superior approaches capable of delivering efficient synthetic approaches to obtain γ-spiro butenolide comprising natural products and their hybrid analogues for further drug discovery and development.
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Affiliation(s)
- Sudip Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, Transit Campus, Govt. ITI Building, NH 59, Engineering School Road, Ganjam-District, Berhampur 760 010, Odisha, India.
| | - Barla Thirupathi
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, Transit Campus, Govt. ITI Building, NH 59, Engineering School Road, Ganjam-District, Berhampur 760 010, Odisha, India.
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3
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Bracegirdle J, Keyzers RA. Marine-derived Polyaromatic Butenolides - Isolation, Synthesis and Biological Evaluations. Curr Pharm Des 2020; 26:4351-4361. [DOI: 10.2174/1381612826666200518110617] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/16/2020] [Indexed: 11/22/2022]
Abstract
Marine invertebrates, especially tunicates, are a lucrative resource for the discovery of new lead compounds
for the development of clinically utilized drugs. This review describes the isolation, synthesis and biological
activities of several classes of marine-derived butenolide natural products, namely rubrolides and related
cadiolides and prunolides. All relevant studies pertaining to these compounds up to the end of 2019 are included.
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Affiliation(s)
- Joe Bracegirdle
- School of Chemical and Physical Sciences, and Centre for Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Robert A. Keyzers
- School of Chemical and Physical Sciences, and Centre for Biodiscovery, Victoria University of Wellington, Wellington 6012, New Zealand
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4
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Yadav P, Pratap R, Ji Ram V. Natural and Synthetic Spirobutenolides and Spirobutyrolactones. ASIAN J ORG CHEM 2020. [DOI: 10.1002/ajoc.202000259] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Pratik Yadav
- Department of Chemistry Kirori Mal College University of Delhi Delhi 110 007 India
| | - Ramendra Pratap
- Department of Chemistry University of Delhi Delhi 110 007 India
| | - Vishnu Ji Ram
- B-67, Eldeco Towne IIM road, PO-Diguria Lucknow-226020 Uttar Pradesh India
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5
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Montagnon T, Kalaitzakis D, Sofiadis M, Vassilikogiannakis G. The reticent tautomer: exploiting the interesting multisite and multitype reactivity of 4-pyrrolin-2-ones. Org Biomol Chem 2020; 18:180-190. [DOI: 10.1039/c9ob02471a] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Multisite and multitype reactivities of the highly versatile and valuable synthetic building block 4-pyrrolin-2-one are covered in this review.
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Affiliation(s)
- Navjeet Kaur
- Department of Chemistry, Banasthali University, Banasthali, India
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7
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Affiliation(s)
- Navjeet Kaur
- Department of Chemistry, Banasthali Vidyapith, Banasthali, India
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8
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Mauger A, Farjon J, Nun P, Coeffard V. One-Pot Synthesis of Functionalized Fused Furans via a BODIPY-Catalyzed Domino Photooxygenation. Chemistry 2018; 24:4790-4793. [DOI: 10.1002/chem.201706087] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Indexed: 12/27/2022]
Affiliation(s)
- Audrey Mauger
- Université de Nantes; CNRS; Chimie Et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM); UMR CNRS 6230; Faculté des Sciences et des Techniques; 2 rue de la Houssinière, BP 92208 44322 Nantes Cedex 3 France
| | - Jonathan Farjon
- Université de Nantes; CNRS; Chimie Et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM); UMR CNRS 6230; Faculté des Sciences et des Techniques; 2 rue de la Houssinière, BP 92208 44322 Nantes Cedex 3 France
| | - Pierrick Nun
- Université de Nantes; CNRS; Chimie Et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM); UMR CNRS 6230; Faculté des Sciences et des Techniques; 2 rue de la Houssinière, BP 92208 44322 Nantes Cedex 3 France
| | - Vincent Coeffard
- Université de Nantes; CNRS; Chimie Et Interdisciplinarité: Synthèse, Analyse et Modélisation (CEISAM); UMR CNRS 6230; Faculté des Sciences et des Techniques; 2 rue de la Houssinière, BP 92208 44322 Nantes Cedex 3 France
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9
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Kotzabasaki V, Vassilikogiannakis G, Stratakis M. Regiocontrolled Synthesis of γ-Hydroxybutenolides via Singlet Oxygen-Mediated Oxidation of 2-Thiophenyl Furans. J Org Chem 2016; 81:4406-11. [DOI: 10.1021/acs.joc.6b00660] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Manolis Stratakis
- Department of Chemistry, University of Crete, 71003 Voutes, Iraklion, Greece
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Affiliation(s)
- Ashwini A. Ghogare
- Department
of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York 11210, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
| | - Alexander Greer
- Department
of Chemistry, Brooklyn College, 2900 Bedford Avenue, Brooklyn, New York 11210, United States
- Ph.D.
Program in Chemistry, The Graduate Center of the City University of New York, 365 Fifth Avenue, New York, New York 10016, United States
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11
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Zhou Y, Ma J, Chen K, Jiang H, Zhu S. Selectivity-switchable oxidation of tetraarylethylenes to fused polycyclic compounds. Chem Commun (Camb) 2016; 52:13345-13348. [DOI: 10.1039/c6cc08155j] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Selectivity-switchable oxidation of furan-containing tetraarylethylenes is reported.
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Affiliation(s)
- Yuefeng Zhou
- Key Laboratory of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- P. R. China
| | - Jun Ma
- Key Laboratory of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- P. R. China
| | - Kai Chen
- Key Laboratory of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- P. R. China
| | - Huanfeng Jiang
- Key Laboratory of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- P. R. China
| | - Shifa Zhu
- Key Laboratory of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou
- P. R. China
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12
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Aikawa K, Asai Y, Hioki Y, Mikami K. Catalytic and highly enantioselective Friedel–Crafts type reactions of heteroaromatic compounds with trifluoropyruvate and glyoxylate by a dicationic palladium complex. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.tetasy.2014.06.013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Montagnon T, Kalaitzakis D, Triantafyllakis M, Stratakis M, Vassilikogiannakis G. Furans and singlet oxygen – why there is more to come from this powerful partnership. Chem Commun (Camb) 2014; 50:15480-98. [DOI: 10.1039/c4cc02083a] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Using the reaction of furans with singlet oxygen as a means to rapidly access huge structural diversity in a green & sustainable way.
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Affiliation(s)
- Tamsyn Montagnon
- Department of Chemistry
- University of Crete
- 71003 Iraklion, Greece
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14
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Takagi A, Ikawa T, Kurita Y, Saito K, Azechi K, Egi M, Itoh Y, Tokiwa H, Kita Y, Akai S. Generation of 3-borylbenzynes, their regioselective Diels–Alder reactions, and theoretical analysis. Tetrahedron 2013. [DOI: 10.1016/j.tet.2013.03.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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15
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16
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Yan Z, Wei W, Xun H, Anguo S. Rose Bengal Immobilized on Wool as an Efficiently “Green” Sensitizer for Photooxygenation Reactions. CHEM LETT 2012. [DOI: 10.1246/cl.2012.1500] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Zhang Yan
- School of Materials Science and Engineering, Beijing Institute of Fashion Technology
| | - Wang Wei
- School of Materials Science and Engineering, Beijing Institute of Fashion Technology
| | - He Xun
- School of Materials Science and Engineering, Beijing Institute of Fashion Technology
| | - Sang Anguo
- School of Materials Science and Engineering, Beijing Institute of Fashion Technology
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17
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Synthesis and biological evaluation of optically active conjugated γ- and δ-lactone derivatives. Bioorg Med Chem Lett 2012; 22:5814-8. [DOI: 10.1016/j.bmcl.2012.07.090] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 07/22/2012] [Accepted: 07/25/2012] [Indexed: 11/21/2022]
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18
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Affiliation(s)
- Dimitris Noutsias
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003 Iraklion, Crete, Greece
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19
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Vassilikogiannakis G, Alexopoulou I, Tofi M, Montagnon T. Singlet oxygen initiated cascade transformation of a simple difuran into the key ABC-ring motif of the pectenotoxins. Chem Commun (Camb) 2011; 47:259-61. [DOI: 10.1039/c0cc01341b] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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20
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Krishnamoorthy R, Lam SQ, Manley CM, Herr RJ. Palladium-catalyzed preparation of Weinreb amides from boronic acids and N-methyl-N-methoxycarbamoyl chloride. J Org Chem 2010; 75:1251-8. [PMID: 20088577 DOI: 10.1021/jo902647h] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A simple protocol for the synthesis of Weinreb benzamides and alpha,beta-unsaturated Weinreb amides through a palladium-catalyzed cross-coupling reaction between organoboronic acids and N-methoxy-N-methylcarbamoyl chloride has been developed. The method is also applicable to the use of potassium organotrifluoroborates.
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Affiliation(s)
- Ravi Krishnamoorthy
- Medicinal Chemistry Department, Albany Molecular Research, Inc., 26 Corporate Circle, P.O. Box 15098, Albany, New York 12212-5098, USA
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21
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Montagnon T, Tofi M, Vassilikogiannakis G. Using singlet oxygen to synthesize polyoxygenated natural products from furans. Acc Chem Res 2008; 41:1001-11. [PMID: 18605738 DOI: 10.1021/ar800023v] [Citation(s) in RCA: 244] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[Reaction: see text]. Singlet oxygen is a powerful tool in the armament of the synthetic organic chemist and possibly in that of nature itself. In this Account, we illustrate a small selection of the many ways singlet oxygen can be harnessed in the laboratory to aid in the construction of the complex molecular motifs found in natural products. A more philosophical question is also addressed: namely, how much do singlet oxygen oxidations influence the biogenesis of these natural products? All the synthetic examples surveyed in this Account can be characterized as belonging to the same class because they all involve the oxidation of a substituted furan nucleus by singlet oxygen. Readily accessible and relatively simple furans can be transformed into a host of complex motifs present in a diverse range of natural products by the action of singlet-oxygen-mediated reaction sequences. These reactions are highly advantageous because they frequently deliver a rapid and dramatic increase in molecular complexity in high yield. Furthermore, an unusually wide structural diversity is exhibited by the molecular motifs obtained from these reaction sequences. For example, relatively minor modifications to the starting substrate and to the reaction conditions may lead to products as variable as spiroketal lactones, 3-keto-tetrahydrofurans, various types of bis-spiroketals, 4-hydroxy cyclopentenones, or spiroperoxylactones. In addition, two more specialized examples are discussed in this Account. The core of the prunolide molecules and the chinensine family of natural products were rapidly synthesized using effective and short singlet oxygen mediated strategies; this adds weight to the assertion that singlet oxygen is a very effective moderator of complex cascade reaction sequences. We also show how our synthetic investigations have provided evidence that these same strategies might be used in the biogenesis of these molecules. In the cases of the chinensines and the litseaverticillols, an entire and diverse family of natural products was synthesized beginning from known naturally occurring furan-bearing terpenes. Additionally, in several cases, intermediates in our syntheses have been isolated from natural sources, which suggests that we have followed the same synthetic paths as nature. Certainly, the limit of the synthetic potential of singlet oxygen has not yet been reached, and we can look forward to seeing the boundaries expand in the future in a slew of new and interesting ways.
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Affiliation(s)
- Tamsyn Montagnon
- University of Crete, Department of Chemistry, Vasilika Vouton, 71003 Iraklion, Crete, Greece
| | - Maria Tofi
- University of Crete, Department of Chemistry, Vasilika Vouton, 71003 Iraklion, Crete, Greece
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22
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Affiliation(s)
- Norbert Hoffmann
- Laboratoire des Réactions Sélectives et Applications, UMR 6519 CNRS et Université de Reims Champagne-Ardenne, UFR Sciences, B.P. 1039, F-51687 Reims, Cedex 02, France
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Margaros I, Montagnon T, Vassilikogiannakis G. Spiroperoxy Lactones from Furans in One Pot: Synthesis of (+)-Premnalane A. Org Lett 2007; 9:5585-8. [DOI: 10.1021/ol702575a] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ioannis Margaros
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003 Iraklion, Crete, Greece
| | - Tamsyn Montagnon
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003 Iraklion, Crete, Greece
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Abstract
Short and efficient syntheses of coronarin E (4) and chinensines A-E (5-9) have been accomplished. The use of two different types of reaction of singlet oxygen ((1)O(2)) lies at the heart of the synthetic strategy. The syntheses have facilitated the clarification of certain previously unknown, or unconfirmed, stereochemical details (the relativity stereochemistries of chinensines D and E and the absolute stereochemistries for all the synthesized family members).
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Affiliation(s)
- Ioannis Margaros
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003 Iraklion, Crete, Greece
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25
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Hou XL, Yang Z, Yeung KS, Wong HN. Five–membered ring systems: furans and benzofurans. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s0959-6380(07)80011-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
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26
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Tofi M, Montagnon T, Georgiou T, Vassilikogiannakis G. Using singlet oxygen to synthesise a [6,6,5]-bis-spiroketal in one-pot from a simple 2,5-disubstituted furan. Org Biomol Chem 2007; 5:772-7. [PMID: 17315063 DOI: 10.1039/b617966e] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Singlet oxygen (1O2) proves to be a powerful tool in mediating the one-pot synthesis of a salinomycin-type [6,6,5]-bis-spiroketal unit starting from a suitably substituted furan nucleus.
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Affiliation(s)
- Maria Tofi
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003 Iraklion, Crete, Greece
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Chen YZ, Wu LZ, Peng ML, Zhang D, Zhang LP, Tung CH. Synthesis of α,β-unsaturated γ-lactones via photooxygenation of 2,3-dihydrofurans followed by ferrous ion-catalyzed gem-dehydration. Tetrahedron 2006. [DOI: 10.1016/j.tet.2006.08.085] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Georgiou T, Tofi M, Montagnon T, Vassilikogiannakis G. A Versatile and General One-Pot Method for Synthesizing Bis-spiroketal Motifs. Org Lett 2006; 8:1945-8. [PMID: 16623591 DOI: 10.1021/ol060558x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] A versatile and general method for the biomimetic construction of [5,5,5]- and [6,5,6]-bis-spiroketals, starting from easily accessible furan nuclei, by means of a powerful one-pot singlet oxygen-mediated cascade sequence is reported.
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Affiliation(s)
- Thomas Georgiou
- Department of Chemistry, University of Crete, Vasilika Vouton, 71003 Iraklion, Crete, Greece
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30
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Tofi M, Georgiou T, Montagnon T, Vassilikogiannakis G. Regioselective Ortho Lithiation of 3-Aryl and 3-Styryl Furans. Org Lett 2005; 7:3347-50. [PMID: 16018657 DOI: 10.1021/ol051205l] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[structure: see text]. An unusual regioselectivity pattern for the ortho lithiation of 3-aryl and 3-styryl furans has been uncovered wherein lithiation occurs preferentially at the sterically encumbered 2-position. The results are attributed, at least in part, to stabilization of the intermediate furyl anion by through-space donation of pi-electron density from the substituent appended at the 3-position to the lithium cation. This ortho lithiation reaction may be applied as a useful synthetic tool for accessing 2,3-disubstituted furans.
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Affiliation(s)
- Maria Tofi
- Department of Chemistry, University of Crete, Greece
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