著者
上野 貢嗣 末宗 洋 佐伯 清太郎 酒井 浄
出版者
The Pharmaceutical Society of Japan
雑誌
Chemical and Pharmaceutical Bulletin (ISSN:00092363)
巻号頁・発行日
vol.33, no.9, pp.4021-4025, 1985-09-25 (Released:2008-03-31)
参考文献数
13
被引用文献数
10 15

The conversion of naturally abundant (+)-limonen-10-ol (2) into the synthetic intermediate (3) for brefeldin A is described. The cis-3, 4-disubstituted cyclopentanone (4), which was easily obtained from 2 by Rh (I)-catalyzed cyclization reaction via the 4-pentenal derivative, could be converted to the target compound 3 via the appropriate modification of substituents on the five-membered ring.
著者
末宗 洋 岩崎 源司 上野 貢嗣 酒井 浄
出版者
The Pharmaceutical Society of Japan
雑誌
Chemical and Pharmaceutical Bulletin (ISSN:00092363)
巻号頁・発行日
vol.32, no.11, pp.4632-4636, 1984-11-25 (Released:2008-03-31)
参考文献数
9
被引用文献数
2 5

The chemical conversion of (+)-limonene (1) and (-)-perillyl alcohol (10) into 9-substituted p-mentha-1, 8 (10)-diene derivatives is described. The lithiated species of 1 and 10 were easily obtained in good yields, by using sec-butyl lithium in N, N, N', N'-tetramethylethylenediamine. The reaction of the lithiated species (A and B) with various electrophiles was completed within 1-2 h to give 9-substituted p-mentha-1, 8 (10)-diene derivatives. The stereochemistry of the chiral center of the starting material was retained in the products. 9-Hydroxy-p-mentha-1, 8 (10)-diene (8) was also obtained by another short sequence of steps. Oxidation of the phenylthio derivative (7) gave the sulfoxide (9). Treatment of 9 with trimethyl phosphite afforded 8.
著者
上野 貢嗣 末宗 洋 酒井 浄
出版者
The Pharmaceutical Society of Japan
雑誌
Chemical and Pharmaceutical Bulletin (ISSN:00092363)
巻号頁・発行日
vol.32, no.9, pp.3768-3769, 1984-09-25 (Released:2008-03-31)
参考文献数
3
被引用文献数
4 12

The key intermediate (11) for the synthesis of carbacyclin (1) was synthesized by the application of a new method for stereoselective five-membered ring formation using Wilkinson complex.
著者
酒井 浄 石黒 靖尚 舟越 和久 上野 貢嗣 末宗 洋
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 26 (ISSN:24331856)
巻号頁・発行日
pp.299-306, 1983-09-15 (Released:2017-08-18)

Variously functionalized cyclopentanones are important as starting materials for the synthesis of natural products. We have succeeded in a simple, highly stereospecific synthesis of five membered ring ketone using Wilkinson complex. Thus, the precursors, 1-al-4-enes(4a-e,11,13) prepared in optically active form from D-limonene, (+)-limonen-10-ol and 1-carvone in three steps were submitted for RhCl(PPh_3)_3-catalyzed cyclization in CH_2Cl_2 to afford the cis-3,4-disubstituted cyclopentanones(14-22) in good yield (Table 2). The following results were obtained in this cyclization. 1) In all cases, the cis-3,4-disubstituted cyclopentanones were stereospecifically obtained as the sole products. 2) The cyclization reaction of the six membered lactols(12,13) was found to proceed very slowly even if at high temperature. 3) The cis-3,4-disubstituted cyclopentanones obtained in this method were also found to be applicable for the synthesis of bicyclic ketone(23). 4) The configurations of 3,4-disubstituents in each compounds were clarified by the way of chemical correlation and spectral analyses. Further application for the synthesis of ent-cis,cis-dihydro-nepetalactone(39) will be discussed.
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)

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 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

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).