The synthesis of methyl 3 alpha, 7 alpha-diacetoxy-11-oxo-5 beta-cholan-24-oate.

ABSTRACT

Reaction of methyl-3 alpha-7 alpha-diacetoxy-11 alpha-bromo-12-oxo-5 beta-cholan-24-oate with sodium borohydride in pyridine solution containing sodium acetate gave the corresponding 11 beta, 12 beta-epoxide in 65% yield. The epoxy-ring was opened with hydrobromic or hydroiodic acid to give the corresponding 12 alpha-halo-11 beta-alcohols, which were converted to the halo-ketones and finally to methyl 3 alpha,7 alpha-diacetoxy-11-oxo-5 beta-cholan-24-oate.