Microbial transformation of 3-hydroxy-5,6-cyclopropanocholestanes - An alternative route to 6-methylsteroids
作者:Jiann-Long Yan、Shoei-Sheng Lee、K.C. Wang
DOI:10.1016/s0039-128x(00)00170-7
日期:2000.12
Incubation of 3 beta -hydroxy-5,6 beta alpha cyclopropano-5 alpha -cholestane (4), 3 beta -hydroxy-5,6 beta -cyclopropano-5 beta -cholestane (5), and 3 beta -hydroxy-5,6 alpha -cyclopropano-5 alpha -cholest-7-ene (6) with Mycobacterium sp. (NRRL B-3805) gave a mixture of side chain cleaved 17-keto steroids as the major products in 52, 57, and 69% yields, respectively. Among these 17-keto steroids, the cyclopropyl ring eliminated product, androst-4-ene-3,17-dione (9), was isolated in 6, 4, and 8% yields, respectively. A cyclopropyl ring migration product, 6 alpha ,7 alpha -cyclopro-panoandrost-4-ene-3,17-dione (16), was isolated from the incubation mixture of 6 in 4% yield, also 10% yield of 16 was obtained when 5,6 alpha -cyclopropano-5 alpha -androst-7-ene-3, 17-dione (12) was incubated. The cyclopropyl ring opening and subsequent reduction followed by oxidation of the two major biotransformation products, 5,6 beta -cyclopropano-5 beta -androsta-3, 17-dione (10) and 5,6 alpha -cyclopropano-5 alpha -androsta-3,17-dione (7), gave 6 beta- and 6 alpha -methylandrost-4-ene-3,17-dione in 60, and 45% yields, respectively. (C) 2000 Elsevier Science Inc. All rights reserved.