P-3 ハウアミンBの合成研究(ポスター発表の部)
書誌事項
- タイトル別名
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- Synthetic Studies on Haouamine B
抄録
Haouamines A (1) and B (2) were isolated from the marine ascidian Aplidium haouarianum collected off the coast of southern Spain. They belong to an unprecedented class of alkdaloids. A unique feature of haouamines is an eleven-membered 3-aza-[7]-paracyclophane moiety, which is so highly strained. The B ring of paracyclophane moiety is non planar and exists in a pseudo-boat conformation. Other features are a diaryl-substituted stereogenic quaternary center and an anti-Bredt double bond. In solution, each haouamine exists as an inseparable mixture of two interconverting isomers. Haouamine A exibits cytotoxic activity against the HT-29 human colon carcinoma cell, and haouamine B does against the MS-1 mice endothelial cells. The novel molecular architecture, the kinetic aspect in the molecule, and the biological activity of haouamines atract a lot of chemists. Therefore, haouamines are challenging synthetic targets. Baran and Burns reported the synthesis of (±)-haouamine A in 2006, and the asymmetric synthesis of (+)-haouamine A in 2008. Recently Baran and co-workers accomplished the synthesis of an atropisomer of haouamine A, and indicated that the inseparable mixture oftwo interconverting isomers in solution was no due to atropisomerism. Weinreb's, Furstner's, and Ishibashi's groups have achieved the formal total synthesis. In this symposium, we report synthetic studies on haouamine B (2) by our original approach. We envisioned that the stereogenic quaternary center could be construced via an intramolecular palladium-catalyzed α-C-arylation, and the anti-Bredt doule bond introduced from a vinylogous amide by TsNHNH_2. The C2-C3 bond formation should be carried out through Suzuki-Miyaura coupling. Construction of the piperidine segment 5 could be completed by the regioselective introductoin of aryl substituents to 4-methoxypyridine (6) usin 3-methoxyphenylboronic acid (7) and 3,5-dimethoxybenzylzinc chloride (8). We also report an introducton of the stereogenic center at C17 position by Comins method.
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 52 (0), 247-252, 2010
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
- 1390001206077516032
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- NII論文ID
- 110009757766
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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