著者

小田 晃造

出版者

九州大学

巻号頁・発行日

1998

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博士論文

著者

末宗 洋 上野 貢嗣 川原 哲也 小田 晃造 舟越 和久 酒井 浄

出版者

天然有機化合物討論会実行委員会

雑誌

天然有機化合物討論会講演要旨集 27 (ISSN:24331856)

巻号頁・発行日

pp.108-114, 1985-09-07 (Released:2017-08-18)

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In the synthesis of natural products consisting of the basic structure of cyclopentane ring, variously functionalized cyclopentanones are required as starting materials. Previously, we succeeded in a simple, highly stereospecific synthesis of the cis-3,4-disubstituted cyclopentanones by the mild reaction with RhCl(PPh_3)_3. By the application of this newer cyclization reaction, we have succeeded in the synthesis of cis,cis-dihydronepetalactone, prostanoic acid, 8-isoprostanoic acid, (+)-brefeldin A and carbacyclin in the optically active form from limonene or Corey lactone. These compounds were synthesized via the following key steps. 1) 3-(3-Oxobutyl)cyclopentanone was easily converted to the deconjugated bicyclic enone (3→4). 2) The regioselective alkylation of limonene was performed by using s-BuLi-TMEDA (1→8). 3) The cis-3,4-disubstituted cyclopentanone from limonen-10-ol could be converted to the trans-3,4-disubstituted cyclo-pentanone by the epimerization (15→16, 22→23).

著者

末宗 洋 小田 晃造 佐伯 清太郎 酒井 浄

出版者

公益社団法人日本薬学会

雑誌

Chemical & pharmaceutical bulletin (ISSN:00092363)

巻号頁・発行日

vol.36, no.1, pp.172-177, 1988-01-25

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This paper describes the conversions of (-)-limonene to four nepetalactones (1,2,ent-3 and 4) in a stereocontrolled manner. The cis-3,4-disubstituted cyclopentanone (5) obtained from (-)-limonene via Rh(I)-catalyzed cyclization of the 4-pentenal, could be converted to the bicyclo[3.3.0]octenone (6). After the stereoselective conversion of 6 into the diastereomeric isomers of the ketones (8 and 16), a sequence of reactions involving the silyl enol ethers (18 and 19), ozonolysis, and subsequent lactonization afforded the target molecules.

著者

末宗 洋 上野 貢嗣 川原 哲也 小田 晃造 舟越 和久 酒井 浄

出版者

天然有機化合物討論会実行委員会

雑誌

天然有機化合物討論会講演要旨集

巻号頁・発行日

vol.27, pp.108-114, 1985

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In the synthesis of natural products consisting of the basic structure of cyclopentane ring, variously functionalized cyclopentanones are required as starting materials. Previously, we succeeded in a simple, highly stereospecific synthesis of the cis-3,4-disubstituted cyclopentanones by the mild reaction with RhCl(PPh_3)_3. By the application of this newer cyclization reaction, we have succeeded in the synthesis of cis,cis-dihydronepetalactone, prostanoic acid, 8-isoprostanoic acid, (+)-brefeldin A and carbacyclin in the optically active form from limonene or Corey lactone. These compounds were synthesized via the following key steps. 1) 3-(3-Oxobutyl)cyclopentanone was easily converted to the deconjugated bicyclic enone (3→4). 2) The regioselective alkylation of limonene was performed by using s-BuLi-TMEDA (1→8). 3) The cis-3,4-disubstituted cyclopentanone from limonen-10-ol could be converted to the trans-3,4-disubstituted cyclo-pentanone by the epimerization (15→16, 22→23).