Synthesis of bile acid analogs: 7-alkylated chenodesoxycholic acids

Article abstract of DOI:10.1016/0039-128X(89)90148-7

This paper describes a method for the preparation of 7-alkylated chenodesoxycholic acids from 3α-hydroxy-7-oxo-5β-cholanoic acid.The synthetic procedure is based upon 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 7β-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.