Une M, Yamanaga K, Mosbach E H, Kuroki S, Hoshita T
Institute of Pharmaceutical Sciences, Hiroshima University School of Medicine, Japan.
Steroids. 1989 Jan-Feb;53(1-2):97-105. doi: 10.1016/0039-128x(89)90148-7.
This paper describes a method for the preparation of 7-alkylated chenodeoxycholic acids from 3 alpha-hydroxy-7-oxo-5 beta-cholanoic acid. The synthetic procedure is based upon a Grignard reaction between the keto bile acid and an alkyl magnesium halide. Under the conditions employed, the introduction of alkyl groups is highly stereoselective. Only 7 beta-alkylated epimers are obtained. The overall yield is several-fold higher than that obtained by the previous method, which involved the preparation of an oxazoline intermediate.
本文描述了一种从3α-羟基-7-氧代-5β-胆烷酸制备7-烷基化鹅去氧胆酸的方法。合成步骤基于酮胆汁酸与烷基卤化镁之间的格氏反应。在所采用的条件下，烷基的引入具有高度的立体选择性。仅得到7β-烷基化的差向异构体。总产率比先前方法（涉及制备恶唑啉中间体）所得的产率高出几倍。
