作者:Emilia Modica、Diego Colombo、Federica Compostella、Antonio Scala、Fiamma Ronchetti
DOI:10.1016/s0039-128x(01)00145-3
日期:2002.2
The reduction of 3-methoxy-estra-1,3,5(10)-trien-17beta-ol (6) and 13-ethyl-3-ethoxy-gona-1,3,5(10)-triene-11alpha,17beta-diol (2) by lithium in ethyl amine in the absence of a proton source is described. Both reductions, contrary to the reports of previous investigators, which indicated the 4-ene to be the main reaction product, gave a complex mixture of products. In the case of the reduction of 2, which is an intermediate in the synthesis of the progestagen desogestrel (1), we obtained the expected known 13-ethyl-gona-4-ene-11alpha,17beta-diol (4) in small amounts and three new steroidal monoenes, 13-ethyl-gona-5(10)-ene-11alpha,17beta-dioI (11), 13-ethyl-gona-5(6)-ene-11alpha,17beta-diol (12), and 13-ethyl-gona-1(10)-ene-11alpha,17beta-diol (13). These compounds were characterized as the 11,17-diacetates with the 5(10)-ene 11 being the major compound. (C) 2002 Elsevier Science Inc. All rights reserved.