37(D-7) ブレベトキシンBの合成研究(口頭発表の部)

• 高村 浩由

  東北大院理

• 西井 広樹

  東北大院理

• 門田 功

  東北大院理

• 山本 嘉則

  東北大院理

書誌事項

タイトル別名

• 37(D-7) Synthetic Study of Brevetoxin B

抄録

Brevetoxin B (1), a potent neurotoxin was isolated from the red tide organism Gymnodinium breve Davis in 1981. The unique structural features and biological activity of this molecule have attracted the attention of synthetic chemists. We have already reported the efficient method for the convergent synthesis of polycyclic ethers via the intramolecular allylation and subsequent ring-closing metathesis. Herein we report the convergent synthesis of the polycyclic framework of 1 based on our own methodology. The reaction of the bicyclic compound 12, prepared from the known compound 9, with the allylic silane 13 in the presence of TMSOTf gave the desired product 14, stereoselectively. The JK ring segment 6 was synthesized in 11 steps including one-carbon elongation from 14. Palladium-catalyzed coupling of the ketene acetal triflate 22, prepared from the known compound 18, and the organozinc reagent 23 gave the enol ether 24, which was converted to the BC ring segment 7. The connection of 7 and the FG ring segment 8 followed by several transformations afforded the allylic stannane 29. The partial reduction of 29 with DIBALH followed by trapping of the resulting aluminum hemiacetal with acetic anhydride provided the acetoxy ether 30. However, the yield was very low. Alternatively, the chlorosulfide 31, prepared from 26, was treated with the alcohol 8 in the presence of AgOTf to provide the O,S-acetal 32. Cyclization of 33 using AgOTf as a Lewis acid gave the desired product 34, stereoselectively. The construction of the E ring and the A ring via ring-closing metathesis afforded the ABCDEFG ring segment 5. The alcohol 5 and the carboxylic acid 6 were connected successfully by Yamaguchi conditions to give the ester 41. The construction of the polycyclic framework of 1 was performed via the intramolecular allylation and subsequent ring-closing metathesis to yield 46. Completion of the total synthesis of 1 is currently under way.

収録刊行物

• 天然有機化合物討論会講演要旨集

  天然有機化合物討論会講演要旨集 46 (0), 197-202, 2004

  天然有機化合物討論会実行委員会

詳細情報

• CRID: 1390282681056588416
• NII論文ID: 110006682418
• DOI: 10.24496/tennenyuki.46.0_197
• ISSN: 24331856
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可