The synthesis of methyl 3 alpha, 7 alpha-diacetoxy-11-oxo-5 beta-cholan-24-oate.
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.
D001894:Borohydrides; D055598:Chemical Phenomena; D002621:Chemistry; D002757:Cholanes / Q000138:chemical synthesis*; D007664:Ketosteroids / Q000138:chemical synthesis; D008722:Methods
D001894:Borohydrides; D002757:Cholanes; D007664:Ketosteroids