P-42 マイトトキシンの部分合成と立体構造解析(ポスター発表の部)
書誌事項
- タイトル別名
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- P-42 SYNTHETIC AND SPECTROSCOPIC STUDIES ON STEREOSTRUCTURE OF MAITOTOXIN
抄録
Maitotoxin (MTX, 1) has been isolated as one of the responsible toxins for ciguatera, which is a form of food poisoning caused by ingestion of coral reef fish. Consequently, the toxin was found to originate from a dinoflagellate Gambierdiscus toxicus. While the planar structure with partial stereochemical assignments for MTX has been reported recently, the stereostructures of acyclic parts, C1-C14, C36-C38, C64-C67, and C135-C142, remains unknown. In this study, we report a synthesis of the tetracyclic fragment corresponding to C56-C75 of MTX and elucidation of the stereochemistry at C64 and C66, which could not be assigned by spectroscopic methods. Preliminary investigations by NOE, ^3JH,H data, and MM2-type calculations (Discover/InsightII) implied that the two hydroxy-bearing carbons had (64S^*, 66S^*) relative stereochemistry. Thus, we first aimed at the synthesis of this stereoisomer. Key steps in our synthesis involved acid-catalyzed 6-endo selective cyclization of epoxy alcohol to construct cis-fused 1,6-dioxadecalin system, and chelation-controlled Aldol condensation of the L/M and N/O ring fragments followed by 1,3-anti reduction of the resulting β-hydroxy ketone, to provide the tetracyclic fragment with (64S, 66S) stereochemistry. Its NMR data agreed extremely well with those of the corresponding part of MTX.
収録刊行物
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- 天然有機化合物討論会講演要旨集
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天然有機化合物討論会講演要旨集 36 (0), 705-712, 1994
天然有機化合物討論会実行委員会
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詳細情報 詳細情報について
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- CRID
- 1390282681054200832
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- NII論文ID
- 110006679356
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- ISSN
- 24331856
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- 本文言語コード
- ja
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- データソース種別
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- JaLC
- CiNii Articles
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- 抄録ライセンスフラグ
- 使用不可