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Abstract

Methyl ester of 3α-acetoxy-12-oxo-9 (11)-cholenic acid and some other analogous compounds were reduced to the corresponding 9(11)-unsaturated 12-hydroxy derivatives by the action of sodium borohydride in the presence of cerium(III) chloride. A part of our work, viz. preparation of steroid hormones from bile acids, was the reduction of 9(11)-unsaturated 12-oxo derivatives of some bile acids, with the view of obtaining the corresponding 9(11)-unsaturated 12-hydroxy derivatives. Hitherto, the only safe route has been hydrogenation of the starting 9(11)-unsaturated 12-oxo derivatives on platinum at elevated pressures, which, preserving the allyl double bond, yields a mixture of the two isomeric 12-hydroxy derivatives.