Microwave-induced organic reactions of bile acids: Esterification, deformylation and deacetylation using mild reagents

Article abstract of DOI:10.1016/0039-128X(95)00004-A

An efficient and convenient procedure for the esterification, deformylation, and deacetylation of bile acids is described.This is achieved by the addition of a catalytic amount of methanesulfonic acid or para-toluene sulfonic acid to a solution of bile acid in methanol in the domestic microwave oven.All these reactions were completed in the microwave oven within 1-3 min at 60percent power (390 W) and the desired bile acids, namely trihydroxy-5β-cholestanoic acid, (23R)-3α,7α,23-trihydroxy-5β-cholan-24-oic acid, ursocholic acid and 7-ketolithocholic acid were isolated in 86-94percent yield. - Keywords: microwave; bile acids; esterification; deformylation; deacetylation; methanesulfonic acid/methanol; para-toluene sulfonic acid/methanol