A new approach to the synthesis of 3β,23-diacetoxy-24-nor-5-cholene from 3β,21-diacetoxy-5-pregnen-20-one
摘要:
Synthesis of 3 beta, 23-diacetoxy-24-nor-5-cholene in six steps from 3 beta, 21-diacetoxy-5-pregnen-20-one has been achieved by a new approach. The method would allow to label the side chain of a bile acid at carbon-atom 21.
A new approach to the synthesis of 3β,23-diacetoxy-24-nor-5-cholene from 3β,21-diacetoxy-5-pregnen-20-one
摘要:
Synthesis of 3 beta, 23-diacetoxy-24-nor-5-cholene in six steps from 3 beta, 21-diacetoxy-5-pregnen-20-one has been achieved by a new approach. The method would allow to label the side chain of a bile acid at carbon-atom 21.
Acyl migration in the Reformatsky reaction of 21-acyloxy-5-pregnen-20-one derivatives with ethyl bromoacetate
作者:Alicia M. Seldes、Eduardo G. Gros
DOI:10.1016/0039-128x(82)90085-x
日期:1982.2
Reformatskyreaction of 3beta, 21-diacyloxy-and 3beta-methoxy-21-acyloxy-5-pregnen-20-one with ethylbromoacetate yields, through an intramolecular 1,2-acyl migration, 38, 20 XI-acyloxy-14alpha-card-5-enolides were converted into the respective 20 XI-hydroxy-14alpha-card-5-enolides and the 14 alpha-carda-5,20(22)-dienolides. Experimental support to the proposed intramolecular 1,2-acyl migration is