1
|
Li G, Sun L, Dickschat JS, Guo Y. Klyflaccilins B‐T, Polyoxgenated Eunicellins from the Soft Coral
Klyxum flaccidum. European J Org Chem 2021. [DOI: 10.1002/ejoc.202001647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Geng Li
- State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park 201203 Shanghai China
- Kekulé-Institute of Organic Chemistry and Biochemistry University of Bonn Gerhard-Domagk-Strasse 1 53121 Bonn Germany
- University of Chinese Academy of Sciences No. 19 A Yuquan Road Beijing 100049 China
| | - Li‐Li Sun
- State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park 201203 Shanghai China
- University of Chinese Academy of Sciences No. 19 A Yuquan Road Beijing 100049 China
| | - Jeroen S. Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry University of Bonn Gerhard-Domagk-Strasse 1 53121 Bonn Germany
| | - Yue‐Wei Guo
- State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences 555 Zu Chong Zhi Road, Zhangjiang Hi-Tech Park 201203 Shanghai China
- University of Chinese Academy of Sciences No. 19 A Yuquan Road Beijing 100049 China
| |
Collapse
|
2
|
Li G, Dickschat JS, Guo YW. Diving into the world of marine 2,11-cyclized cembranoids: a summary of new compounds and their biological activities. Nat Prod Rep 2020; 37:1367-1383. [DOI: 10.1039/d0np00016g] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
This review summarises new marine 2,11-cyclized cembranoids from the past decade in a structured presentation according to their hypothetical biosynthesis.
Collapse
Affiliation(s)
- Geng Li
- State Key Laboratory of Drug Research
- Shanghai Institute of Materia Medica
- Chinese Academy of Sciences
- Shanghai 201203
- China
| | - Jeroen S. Dickschat
- Kekulé-Institute for Organic Chemistry and Biochemistry
- University of Bonn
- 53121 Bonn
- Germany
| | - Yue-Wei Guo
- State Key Laboratory of Drug Research
- Shanghai Institute of Materia Medica
- Chinese Academy of Sciences
- Shanghai 201203
- China
| |
Collapse
|
3
|
Hooper JF, James NC, Bozkurt E, Aviyente V, White JM, Holland MC, Gilmour R, Holmes AB, Houk KN. Medium-Ring Effects on the Endo/Exo Selectivity of the Organocatalytic Intramolecular Diels–Alder Reaction. J Org Chem 2015; 80:12058-75. [DOI: 10.1021/acs.joc.5b02037] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joel F. Hooper
- School
of Chemistry, Bio21 Institute, The University of Melbourne, 30 Flemington
Road, Melbourne, Victoria 3010, Australia
| | - Natalie C. James
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| | - Esra Bozkurt
- Laboratory
of Computational Chemistry and Biochemistry, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Viktorya Aviyente
- Department
of Chemistry, Boğaziçi University, Bebek 34342, Istanbul, Turkey
| | - Jonathan M. White
- School
of Chemistry, Bio21 Institute, The University of Melbourne, 30 Flemington
Road, Melbourne, Victoria 3010, Australia
| | - Mareike C. Holland
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Ryan Gilmour
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität Münster, 48149 Münster, Germany
| | - Andrew B. Holmes
- School
of Chemistry, Bio21 Institute, The University of Melbourne, 30 Flemington
Road, Melbourne, Victoria 3010, Australia
| | - K. N. Houk
- Department
of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, United States
| |
Collapse
|
4
|
Clark JS, Delion L, Farrugia LJ. Synthesis of four diastereomers of sclerophytin F and structural reassignment of several sclerophytin natural products. Chemistry 2015; 21:4772-80. [PMID: 25663662 DOI: 10.1002/chem.201406051] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Indexed: 11/09/2022]
Abstract
Synthesis of the triol that has been proposed to be the marine natural product sclerophytin F has been completed along with the syntheses of three diastereomers. Comparison of the NMR spectroscopic data for all four compounds to the data reported for the natural product reveals that sclerophytin F is not the 3S diastereomer of sclerophytin A as proposed by Friedrich and Paquette. Re-analysis of the NMR spectroscopic data for known sclerophytin natural products and synthetic analogues leads to the conclusion that sclerophytins E and F are the same compound. This finding has allowed structural reassignment of several other cladiellin natural products.
Collapse
Affiliation(s)
- J Stephen Clark
- WestCHEM, School of Chemistry, Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ (UK).
| | | | | |
Collapse
|
5
|
Clark JS, Delion L, Farrugia LJ. Total synthesis of the purported structure of sclerophytin F. Org Lett 2014; 16:4300-3. [PMID: 25068316 DOI: 10.1021/ol5020152] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis of the compound that has been proposed to be the natural product sclerophytin F has been completed from a known vinylogous carbonate. The synthetic strategy relied upon rearrangement of a catalytically generated ylide-like intermediate to produce an oxabicyclo[6.2.1]-5-undecen-9-one and an intermolecular Diels-Alder reaction to construct the complete tricyclic core found in the natural product. Comparison of the spectroscopic data for synthetic material to that reported for sclerophytin F shows that the natural product does not have the revised structure possessing the 3S configuration (*) proposed previously.
Collapse
Affiliation(s)
- J Stephen Clark
- WestCHEM, School of Chemistry, Joseph Black Building, University of Glasgow , University Avenue, Glasgow, G12 8QQ, United Kingdom
| | | | | |
Collapse
|
6
|
Efficient Total Synthesis of Bioactive Natural Products: A Personal Record. CHEM REC 2014; 14:606-22. [DOI: 10.1002/tcr.201402015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Indexed: 11/07/2022]
|
7
|
Yue G, Zhang Y, Fang L, Li CC, Luo T, Yang Z. Collective Synthesis of Cladiellins Based on the Gold-Catalyzed Cascade Reaction of 1,7-Diynes. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201309449] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
8
|
Yue G, Zhang Y, Fang L, Li CC, Luo T, Yang Z. Collective Synthesis of Cladiellins Based on the Gold-Catalyzed Cascade Reaction of 1,7-Diynes. Angew Chem Int Ed Engl 2014; 53:1837-40. [DOI: 10.1002/anie.201309449] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Indexed: 11/07/2022]
|
9
|
Tai CJ, Su JH, Huang CY, Huang MS, Wen ZH, Dai CF, Sheu JH. Cytotoxic and anti-inflammatory eunicellin-based diterpenoids from the soft coral Cladiella krempfi. Mar Drugs 2013; 11:788-99. [PMID: 23481676 PMCID: PMC3705370 DOI: 10.3390/md11030788] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 02/06/2013] [Accepted: 02/19/2013] [Indexed: 11/23/2022] Open
Abstract
Five new eunicellin-based diterpenoids, krempfielins E–I (1–5) and seven known compounds (6–12) were isolated from the organic extract of a Taiwanese soft coral Cladiella krempfi. The structures of the new metabolites were elucidated on the basis of extensive spectroscopic analysis. Metabolites 5, 6, 10 and 12 were shown to exhibit cytotoxicity against a limited panel of cancer cell lines. Furthermore, compounds 6 and 10 could potently inhibit the accumulation of the pro-inflammatory iNOS protein, and 6 and 12 could significantly reduce the expression of COX-2 protein in LPS-stimulated RAW264.7 macrophage cells.
Collapse
Affiliation(s)
- Chi-Jen Tai
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan; E-Mails: (C.-J.T.); (C.-Y.H.); (Z.-H.W.)
| | - Jui-Hsin Su
- National Museum of Marine Biology & Aquarium, Pingtung 944, Taiwan; E-Mail:
- Graduate Institute of Marine Biotechnology, National Dong Hwa University, Pingtung 944, Taiwan
| | - Chiung-Yao Huang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan; E-Mails: (C.-J.T.); (C.-Y.H.); (Z.-H.W.)
| | - Ming-Shyan Huang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan; E-Mail:
- Center of Excellence for Environmental Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Zhi-Hong Wen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan; E-Mails: (C.-J.T.); (C.-Y.H.); (Z.-H.W.)
| | - Chang-Feng Dai
- Institute of Oceanography, National Taiwan University, Taipei 112, Taiwan; E-Mail:
| | - Jyh-Horng Sheu
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan; E-Mails: (C.-J.T.); (C.-Y.H.); (Z.-H.W.)
- Division of Marine Biotechnology, Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 804, Taiwan
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +886-7-525-2000 (ext. 5030); Fax: +886-7-525-5020
| |
Collapse
|
10
|
Clark JS, Berger R, Hayes ST, Senn HM, Farrugia LJ, Thomas LH, Morrison AJ, Gobbi L. Total Syntheses of Multiple Cladiellin Natural Products by Use of a Completely General Strategy. J Org Chem 2012; 78:673-96. [DOI: 10.1021/jo302542h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [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
| | - Raphaëlle Berger
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Stewart T. Hayes
- School of Chemistry, University of Nottingham, University Park, Nottingham
NG7 2RD, United Kingdom
| | - Hans Martin Senn
- WestCHEM, School of Chemistry,
Joseph Black Building, University of Glasgow, University Avenue, Glasgow G12 8QQ, United Kingdom
| | - Louis J. Farrugia
- 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
| | | | - Luca Gobbi
- Discovery Chemistry (PRCB), F. Hoffmann-La Roche Ltd. Pharmaceuticals Division,
CH-4070 Basel, Switzerland
| |
Collapse
|
11
|
Welford AJ, Collins I. The 2,11-cyclized cembranoids: cladiellins, asbestinins, and briarellins (period 1998-2010). JOURNAL OF NATURAL PRODUCTS 2011; 74:2318-2328. [PMID: 21970540 DOI: 10.1021/np200125v] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The 2,11-cyclized cembranoids are isolated from marine invertebrates of Octocorallia species. They are a very interesting class of natural products sharing a common oxatricyclo[6.6.1.0(2,7)]pentadecane core and carrying a varied substituent pattern. This review presents their structural diversity along with the reported biological activities. The 2,11-cyclized cembranoids were comprehensively reviewed previously in 1998, and this contribution will serve as an update of that work. Since 1998 a number of structural assignments of the isolated products have been revised, some as a result of total synthesis efforts. The chemical reactivity of several of the natural compounds has been studied, and the relevance of these findings to the biosynthesis or the generation of isolation artifacts is discussed. The wide range of biological activities displayed by the 2,11-cyclized cembranoids justifies the interest shown within the synthetic chemistry community and suggests that this class of natural products remains a fruitful area for future synthetic and biological research.
Collapse
Affiliation(s)
- Amanda J Welford
- Cancer Research UK Cancer Therapeutics Unit, Institute of Cancer Research, 15 Cotswold Road, Sutton, Surrey SM2 5NG, UK
| | | |
Collapse
|
12
|
Abstract
The total syntheses of (+)-vigulariol and (-)-sclerophytin A are reported in 15 steps and 16 steps, respectively, from a known compound. The flexible, readily scalable synthetic strategy allows for rapid construction of a critical tricyclic intermediate and is demonstrated via the synthesis of these two marine natural products. A key reaction in this synthetic protocol is a combination Wittig/intramolecular Diels-Alder cycloaddition.
Collapse
Affiliation(s)
- Michael T Crimmins
- Kenan Laboratory of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA.
| | | | | |
Collapse
|
13
|
Hassan HM, Elnagar AY, Khanfar MA, Sallam AA, Mohammed R, Shaala LA, Youssef DT, Hifnawy MS, El Sayed KA. Design of semisynthetic analogues and 3D-QSAR study of eunicellin-based diterpenoids as prostate cancer migration and invasion inhibitors. Eur J Med Chem 2011; 46:1122-30. [DOI: 10.1016/j.ejmech.2011.01.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Revised: 01/08/2011] [Accepted: 01/14/2011] [Indexed: 10/18/2022]
|
14
|
Chen BW, Chang SM, Huang CY, Chao CH, Su JH, Wen ZH, Hsu CH, Dai CF, Wu YC, Sheu JH. Hirsutalins A-H, eunicellin-based diterpenoids from the soft coral Cladiella hirsuta. JOURNAL OF NATURAL PRODUCTS 2010; 73:1785-1791. [PMID: 20979397 DOI: 10.1021/np100401f] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Eight new eunicellin-base diterpenoids, hirsutalins A-H (1-8), were isolated from the soft coral Cladiella hirsuta. Their structures were elucidated by spectroscopic methods, particularly in 1D and 2D NMR experiments. The absolute configuration of 1 was determined by Mosher's method. Compounds 1, 5, and 6 have been shown to exhibit cytotoxicity toward several cancer cell lines. Compounds 2-4 and 8 were found to display significant in vitro anti-inflammatory activity in LPS-stimulated RAW264.7 macrophage cells by inhibiting the expression of the iNOS protein, with compound 2 also effectively reducing the level of COX-2 protein.
Collapse
Affiliation(s)
- Bo-Wei Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung 804, Taiwan, Republic of China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Wang B, Ramirez AP, Slade JJ, Morken JP. Enantioselective synthesis of (-)-sclerophytin A by a stereoconvergent epoxide hydrolysis. J Am Chem Soc 2010; 132:16380-2. [PMID: 21028899 DOI: 10.1021/ja108185z] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cytotoxic natural product (-)-sclerophytin A was constructed in 13 steps from geranial. Highlights from the synthesis are a stereoselective Oshima-Utimoto reaction, a Shibata-Baba indium-promoted radical cyclization, and a novel stereoconvergent epoxide hydrolysis.
Collapse
Affiliation(s)
- Bin Wang
- Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States
| | | | | | | |
Collapse
|
16
|
Hassan HM, Khanfar MA, Elnagar AY, Mohammed R, Shaala LA, Youssef DTA, Hifnawy MS, El Sayed KA. Pachycladins A-E, prostate cancer invasion and migration inhibitory Eunicellin-based diterpenoids from the red sea soft coral Cladiella pachyclados. JOURNAL OF NATURAL PRODUCTS 2010; 73:848-853. [PMID: 20420415 DOI: 10.1021/np900787p] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Alcyonaria species are among the important marine invertebrate classes that produce a wealth of chemically diverse bioactive diterpenes. Examples of these are the potent microtubule disruptor sarcodictyins and eleutherobin. The genus Cladiella has proven to be a rich source of cytotoxic eunicellin-based diterpenoids. Five new eunicellin diterpenes, pachycladins A-E (1-5), were isolated from the Red Sea soft coral Cladiella pachyclados. The known sclerophytin A Cladiellisin, 3-acetylcladiellisin, 3,6-diacetylcladiellisin, (+)-polyanthelin A, klysimplexin G, klysimplexin E, sclerophytin F methyl ether, (6Z)-cladiellin (cladiella-6Z,11(17)-dien-3-ol), sclerophytin B, and patagonicol were also identified. The structures of the isolated compounds were elucidated by extensive interpretation of their spectroscopic data. These compounds were evaluated for their ability to inhibit growth, proliferation, invasion, and migration of the prostate cancer cells PC-3. Some of the new metabolites exhibited significant anti-invasive activity.
Collapse
Affiliation(s)
- Hossam M Hassan
- Department of Basic Pharmaceutical Sciences, College of Pharmacy, University of Louisiana at Monroe, Monroe, Louisiana 71201, USA
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Elyashberg M, Williams AJ, Blinov K. Structural revisions of natural products by Computer-Assisted Structure Elucidation (CASE) systems. Nat Prod Rep 2010; 27:1296-328. [DOI: 10.1039/c002332a] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
18
|
Ellis JM, Crimmins MT. Strategies for the total synthesis of C2-C11 cyclized cembranoids. Chem Rev 2009; 108:5278-98. [PMID: 18942794 DOI: 10.1021/cr078117u] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J Michael Ellis
- Department of Chemistry, Venable and Kenan Laboratories of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA
| | | |
Collapse
|
19
|
Bateman TD, Joshi AL, Moon K, Galitovskaya EN, Upreti M, Chambers TC, McIntosh MC. Synthesis and anticancer activity of sclerophytin-inspired hydroisobenzofurans. Bioorg Med Chem Lett 2009; 19:6898-901. [PMID: 19896844 DOI: 10.1016/j.bmcl.2009.10.079] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/15/2009] [Accepted: 10/19/2009] [Indexed: 11/29/2022]
Abstract
Three structurally related sets of hydroisobenzofuran analogs of sclerophytin A were prepared in three or four steps from (S)-(+)-carvone via an aldol-cycloaldol sequence. The most potent members of each set of analogs exhibited IC(50)'s of 1-3 microM in growth inhibitory assays against KB3 cells. The NCI 60-cell line 5-dose assay for analog 6h revealed a GI(50)=0.148 microM and LC(50)=9.36 microM for the RPMI-8226 leukemia cell line, and a GI(50)=0.552 microM and LC(50)=26.8 microM for the HOP-92 non-small cell lung cancer cell line.
Collapse
Affiliation(s)
- T David Bateman
- Department of Chemistry and Biochemistry, 119 Chemistry Building, University of Arkansas, Fayetteville, AR 72701, USA
| | | | | | | | | | | | | |
Collapse
|
20
|
Corminboeuf O, Overman LE, Pennington LD. A unified strategy for enantioselective total synthesis of cladiellin and briarellin diterpenes: total synthesis of briarellins E and F and the putative structure of alcyonin and revision of its structure assignment. J Org Chem 2009; 74:5458-70. [PMID: 19534538 PMCID: PMC2744073 DOI: 10.1021/jo9010156] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Enantioselective total syntheses of briarellin E (12) and briarellin F (13), as well as the structure originally proposed for the cladiellin diterpene alcyonin (10), have been realized. Comparison of the spectral data for synthetic 10, natural alcyonin, cladiellisin (33), and cladiellaperoxide (34), as well as chemical transformations of 10 and natural alcyonin, suggest that the structure of this coral metabolite is allylic peroxide 11. The unified approach detailed herein can be used to access both C4-deoxygenated and C4-oxygenated cladiellins and briarellins. The central step in these syntheses is acid-promoted condensation of (Z)-alpha,beta-unsaturated aldehydes 17 with cyclohexadienyl diols 18 to form intermediates 16 incorporating the hexahydroisobenzofuran core and five stereocenters of these marine diterpenes (Scheme 1 ).
Collapse
Affiliation(s)
| | - Larry E. Overman
- Department of Chemistry, 1102 Natural Sciences II, University of California, Irvine, California 92697-2025
| | | |
Collapse
|
21
|
Kwan EE, Huang SG. Structural Elucidation with NMR Spectroscopy: Practical Strategies for Organic Chemists. European J Org Chem 2008. [DOI: 10.1002/ejoc.200700966] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Eugene E. Kwan
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA, Fax: +1‐617‐495‐1460
| | - Shaw G. Huang
- Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA, Fax: +1‐617‐495‐1460
| |
Collapse
|
22
|
Montaña ÁM, Ponzano S, Kociok-Köhn G, Font-Bardia M, Solans X. Versatile Methodology to Synthesize Oxygen-Bridged Nine- and Ten-Membered Cycloalkanes by the Hypoiodite Reaction. European J Org Chem 2007. [DOI: 10.1002/ejoc.200700172] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
23
|
Hutchison JM, Lindsay HA, Dormi SS, Jones GD, Vicic DA, McIntosh MC. Approach to the synthesis of cladiell-11-ene-3,6,7-triol. Org Lett 2007; 8:3663-5. [PMID: 16898786 DOI: 10.1021/ol061072j] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] The synthesis of an advanced intermediate in the synthesis of the title compound has been achieved. Key steps include an Ireland-Claisen rearrangement to install the C7 tertiary alcohol stereocenter, an SN2' reaction of an alkoxymethyl Cu reagent, and a diastereoselective Re-catalyzed allylic alcohol transposition.
Collapse
|
24
|
Nicolaou KC, Snyder SA. Chasing molecules that were never there: misassigned natural products and the role of chemical synthesis in modern structure elucidation. Angew Chem Int Ed Engl 2007; 44:1012-1044. [PMID: 15688428 DOI: 10.1002/anie.200460864] [Citation(s) in RCA: 479] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Over the course of the past half century, the structural elucidation of unknown natural products has undergone a tremendous revolution. Before World War II, a chemist would have relied almost exclusively on the art of chemical synthesis, primarily in the form of degradation and derivatization reactions, to develop and test structural hypotheses in a process that often took years to complete when grams of material were available. Today, a battery of advanced spectroscopic methods, such as multidimensional NMR spectroscopy and high-resolution mass spectrometry, not to mention X-ray crystallography, exist for the expeditious assignment of structures to highly complex molecules isolated from nature in milligram or sub-milligram quantities. In fact, it could be argued that the characterization of natural products has become a routine task, one which no longer even requires a reaction flask! This Review makes the case that imaginative detective work and chemical synthesis still have important roles to play in the process of solving nature's most intriguing molecular puzzles.
Collapse
Affiliation(s)
- K C Nicolaou
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858-784-2469
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Scott A Snyder
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858-784-2469
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| |
Collapse
|
25
|
Gilmour R, Prior TJ, Burton JW, Holmes AB. An organocatalytic approach to the core of eunicellin. Chem Commun (Camb) 2007:3954-6. [PMID: 17896044 DOI: 10.1039/b709322e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A stereocontrolled synthesis of the core of eunicellin is described featuring a Claisen rearrangement and a diastereoselective organocatalytic Diels-Alder reaction as the key steps.
Collapse
Affiliation(s)
- Ryan Gilmour
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UKCB2 1EW
| | | | | | | |
Collapse
|
26
|
Molander GA, Czakó B, St Jean DJ. A general route toward the synthesis of the cladiellin skeleton utilizing a SmI2-mediated cyclization. J Org Chem 2006; 71:1172-80. [PMID: 16438535 PMCID: PMC2505338 DOI: 10.1021/jo052290d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An efficient synthesis of the cladiellin skeleton is reported utilizing methods that were previously developed in this laboratory. The approach is based on a SmI(2)-mediated cyclization reaction for the construction of the oxacyclononane unit. A [4 + 3] annulation strategy was used to create the octahydroisobenzofuran moiety. This route provides the cladiellin skeleton in only 14 steps without the use of protecting groups. The present approach also enabled the synthesis of the 3,7-diastereomer of the natural product polyanthellin A.
Collapse
Affiliation(s)
- Gary A Molander
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.
| | | | | |
Collapse
|
27
|
Nicolaou KC, Snyder SA. Die Jagd auf Moleküle, die nie existiert haben: Falsch zugeordnete Naturstoffstrukturen und die Rolle der chemischen Synthese in der modernen Strukturaufklärung. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200460864] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- K. C. Nicolaou
- Department of Chemistry und The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858‐784‐2469
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Scott A. Snyder
- Department of Chemistry und The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA, Fax: (+1) 858‐784‐2469
- Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| |
Collapse
|
28
|
Chill L, Berrer N, Benayahu Y, Kashman Y. Eunicellin diterpenes from two Kenyan soft corals. JOURNAL OF NATURAL PRODUCTS 2005; 68:19-25. [PMID: 15679311 DOI: 10.1021/np049772p] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Six new eunicellin diterpenes designated klyxumines A and B (1, 2) and epoxycladines A-D (3-6) were isolated from Klyxum flaccidum and Cladiella kashmani, collected in Kenya. The structures of the compounds were elucidated by interpretation of MS, COSY, HMQC, HMBC, and NOESY data.
Collapse
Affiliation(s)
- Liat Chill
- School of Chemistry, Tel-Aviv University, Ramat Aviv 69978, Israel
| | | | | | | |
Collapse
|
29
|
|
30
|
Abstract
The structural designation A originally made by Sharma and Alam to sclerophytin A was considered to be ambiguous and so notably strained relative to B that the latter was targeted for de novo synthesis (Scheme 1). Our two successful routes began with (5S)-(d-menthyloxy)-2(5H)-furanone and involved the application of cycloaddition, Claisen ring expansion, transannular oxymercuration, and 1,2-carbonyl transposition tactics to arrive at B. It was immediately apparent from polarity considerations and spectroscopic data that the antileukemic marine metabolite in question was in need of more deep-seated structural revision. Following close re-examination of an acquired authentic sample by advanced NMR techniques, the strong inference was made that sclerophytin A actually lacked a second oxygen bridge and was in reality the triol C. This conclusion was unequivocally confirmed by diverting an advanced intermediate generated earlier into a short sequence beginning with regiocontrolled dihydroxylation and terminating with configurational inversion at the secondary carbinol center. The status of other members of this series is also presented.
Collapse
Affiliation(s)
- L A Paquette
- Evans Chemical Laboratories, The Ohio State University, Columbus 43210, USA.
| |
Collapse
|
31
|
Jung ME, Pontillo J. Synthetic approach to analogues of the original structure of sclerophytin A. J Org Chem 2002; 67:6848-51. [PMID: 12227825 DOI: 10.1021/jo016246j] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A route to analogues of the original structure of sclerophytin A is described. The beta-anomer of dideoxyribosyl nitriles 10a,b (prepared from glutamic acid) was converted into the methyl ketone 11. Addition of a silylated acetylide to 11 in diethyl ether/trimethylamine gave mainly 22a. Alkylation with methallyl halide and ozonolysis gave the ketone 24, which was then converted by hydrogenation and a second ozonolysis into the keto aldehyde 26. A two-step aldol process afforded the desired 3-pyrone 27 in good overall yield. However, several methods for the conversion of this enone 27 into the desired sclerophytin analogue 2 failed.
Collapse
Affiliation(s)
- Michael E Jung
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA.
| | | |
Collapse
|
32
|
Friedrich D, Paquette LA. Structural and stereochemical reassessment of sclerophytin-type diterpenes. JOURNAL OF NATURAL PRODUCTS 2002; 65:126-130. [PMID: 11858742 DOI: 10.1021/np0103822] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A complete reassessment of the structural assignments of the sclerophytin diterpenes is provided.
Collapse
Affiliation(s)
- Dirk Friedrich
- Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA
| | | |
Collapse
|
33
|
Molander GA, Jeffrey SC. Synthesis of the core ring system of the sclerophytin diterpenes utilizing a Lewis acid-promoted [4+3] annulation strategy. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(01)02190-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
34
|
MacMillan DW, Overman LE, Pennington LD. A general strategy for the synthesis of cladiellin diterpenes: enantioselective total syntheses of 6-acetoxycladiell-7(16),11-dien-3-ol (deacetoxyalcyonin acetate), cladiell-11-ene-3,6,7-triol, sclerophytin A, and the initially purported structure of sclerophytin A. J Am Chem Soc 2001; 123:9033-44. [PMID: 11552811 DOI: 10.1021/ja016351a] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enantioselective total syntheses of the cladiellin diterpenes, 6-acetoxycladiell-7(16),11-dien-3-ol (deacetoxyalcyonin acetate, 6), cladiell-11-ene-3,6,7-triol (1), sclerophytin A (8), and tetracyclic diether 7, have been achieved by differential elaboration of tricyclic allylic alcohol 57. The central step in these syntheses is acid-promoted condensation of alpha,beta-unsaturated aldehydes 45, 69 or 87, and cyclohexadienyl diol 44 to form, with complete stereocontrol, the hexahydroisobenzofuran core and five stereocenters of these cladiellin diterpenes. These syntheses also feature stereospecific photolytic deformylation of beta,gamma-unsaturated aldehydes 46, 70, and 71 to remove the extraneous carbon introduced in the Prins-pinacol step; chemo- and stereoselective hydroxyl-directed epoxidation of 49, 72, and 90 followed by regioselective reductive opening with hydride to install the C3 tertiary hydroxyl group; and a diastereoselective Nozaki-Hiyama-Kishi cyclization of iodoaldehyde 56 to forge the oxacyclononane ring and the C6 hydroxyl stereocenter. Other key transformations include chemo- and stereoselective hydroxyl-directed epoxidation of tricyclic allylic alcohol 57 followed by regioselective reductive opening with hydride to install the C7 tertiary hydroxyl center of 1 and 8; chemo-, regio-, and stereoselective intramolecular oxymercuration-reductive demercuration of dienyl diol 62 to form the bridging tetrahydropyran ring of tetracyclic diether 7; and photochemical isomerization of the endocyclic double bond of 92 and 1 to give exocyclic congeners 7 and 8. The absolute stereochemistry of the synthetic products originates from two chiral nonracemic starting materials, (S)-(+)-carvone and (S)-(-)-glycidol. These syntheses define a versatile and concise strategy for the total synthesis of cladiellin diterpenes and provide additional illustrations of the uncommon utility of pinacol-terminated cationic cyclizations for the stereocontrolled synthesis of complex oxacyclic products.
Collapse
Affiliation(s)
- D W MacMillan
- Department of Chemistry, 516 Rowland Hall, University of California, Irvine, CA 92697-2025, USA
| | | | | |
Collapse
|
35
|
Bernardelli P, Moradei OM, Friedrich D, Yang J, Gallou F, Dyck BP, Doskotch RW, Lange T, Paquette LA. Total asymmetric synthesis of the putative structure of the cytotoxic diterpenoid (-)-sclerophytin a and of the authentic natural sclerophytins A and B. J Am Chem Soc 2001; 123:9021-32. [PMID: 11552810 DOI: 10.1021/ja011285y] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An enantioselective synthetic route to the thermodynamically most stable diastereomer of the structure assigned to sclerophytin A (5) has been realized. The required tricyclic ketone 33 was prepared by sequential Tebbe-Claisen rearrangement of lactones 29 and 30, which originated from the Diels-Alder cycloaddition of Danishefsky's diene to (5S)-5-(d-menthyloxy)-2(5H)-furanone (14). An allyl and a cyano group were introduced into the resulting adduct by means of stereocontrolled allylindation under aqueous Barbier-like conditions and by way of cyanotrimethylsilane, respectively. Following stereocontrolled nucleophilic addition of a methyl group to 33, ring A was elaborated by formation of the silyl enol ether, ytterbium triflate-catalyzed condensation with formaldehyde, O-silylation, and Cu(I)-promoted 1,4-addition of isopropylmagnesium chloride. The superfluous ketone carbonyl was subsequently removed and the second ether bridge introduced by means of oxymercuration chemistry. Only then was the exocyclic methylene group unmasked via elimination. An alternative approach to the alpha-carbinol diastereomer proceeds by initial alpha-oxygenation of 37 and ensuing 1,2-carbonyl transposition. Neither this series of steps nor the Wittig olefination to follow induced epimerization at C10. Through deployment of oxymercuration chemistry, it was again possible to elaborate the dual oxygen-bridge network of the target ring system. Oxidation of the organomercurial products with O(2) in the presence of sodium borohydride furnished 72, which was readily separated from its isomer 73 after oxidation to 61. Hydride attack on this ketone proceeded with high selectivity from the beta-direction to deliver (-)-60. Comparison of the high-field (1)H and (13)C NMR properties and polarity of synthetic 5 with natural material required that structural revision be made. Following a complete spectral reassessment of the structural assignments to many sclerophytin diterpenes, a general approach to sclerophytin A, three diastereomers thereof, and of sclerophytin B was devised. The presence of two oxygen bridges as originally formulated was thereby ruled out, and absolute configurations were properly determined. Key elements of the strategy include dihydroxylation of a medium-ring double bond, oxidation of the secondary hydroxyl in the two resulting diols, unmasking of an exocyclic methylene group at C-11, and stereocontrolled 1,2-reduction of the alpha-hydroxy ketone functionality made available earlier.
Collapse
Affiliation(s)
- P Bernardelli
- Department of Chemistry, The Ohio State University, Columbus, OH 43210, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Gallou F, MacMillan DW, Overman LE, Paquette LA, Pennington LD, Yang J. Enantioselective syntheses of authentic sclerophytin A, sclerophytin B, and cladiell-11-ene-3,6,7-triol. Org Lett 2001; 3:135-7. [PMID: 11429857 DOI: 10.1021/ol000345m] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[figure: see text] Two distinctively different total syntheses of natural sclerophytin A in its revised structural formulation are reported. The first proceeds from (S)-carvone via a cladiellene triol and involves photoisomerization of the double bond. The second route makes use of (5S)-5-(d-menthyloxy)-2(5H)-furanone, which is subjected to cycloaddition, Claisen ring expansion, and regiocontrolled dihydroxylation tactics.
Collapse
Affiliation(s)
- F Gallou
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA
| | | | | | | | | | | |
Collapse
|
37
|
Five-Membered Ring Systems Furans and Benzofurans. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0959-6380(01)80009-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
|
38
|
Overman LE, Pennington LD. Total synthesis of the supposed structure of (-)-sclerophytin A and an improved route to (-)-7-deacetoxyalcyonin acetate. Org Lett 2000; 2:2683-6. [PMID: 10990427 DOI: 10.1021/ol006236p] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[reaction: see text]Stereoselective acid-catalyzed rearrangement of 15-->16 is the central step in total syntheses of (-)-7-deacetoxyalcyonin acetate (1) and the compound with the alleged structure of sclerophytin A (2). Since tetracyclic diether 2 is not identical to sclerophytin A, the structure of this antineoplastic marine diterpene must be revised. The conversion of 15-->16 demonstrates for the first time that tetrahydrofurans containing (Z)-1-methylalkenyl side chains can be prepared by Prins-pinacol rearrangements.
Collapse
Affiliation(s)
- L E Overman
- Department of Chemistry, University of California, Irvine 92697-2025, USA.
| | | |
Collapse
|
39
|
Paquette LA, Moradei OM, Bernardelli P, Lange T. Synthesis of the alleged structure of sclerophytin A. The setting of two oxygen bridges within the fused cyclodecanol B ring is not Nature's Way. Org Lett 2000; 2:1875-8. [PMID: 10891180 DOI: 10.1021/ol000083o] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
[reaction: see text] The structure attributed to sclerophytin A, a cytotoxic soft coral metabolite, was synthesized in an enantioselective manner from (5S)-5-(d-menthyloxy)-2(5H)-furanone. The spectral properties and polarity of the synthetic product require that the structural assignment to the natural material be revised.
Collapse
Affiliation(s)
- L A Paquette
- Evans Chemical Laboratories, The Ohio State University, Columbus, Ohio 43210, USA.
| | | | | | | |
Collapse
|