Collect. Czech. Chem. Commun. 1981, 46, 2898-2905
https://doi.org/10.1135/cccc19812898

Synthesis of 19-nor-10β-vinyl-5α-cholestane and its 5β-epimer

Pavel Kočovský

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6

Abstract

The title compound IX was synthesized from the monoacetate I in seven steps. The key point of the synthesis is selective hydrolysis of the diacetate II to III and removal of the substituent from the position 3 (IV → V). The 5β-isomeric olefin XX was prepared from the monoester XI in a similar manner. Conformational factors leading to differences in the reactivity of the ester groups in positions 3 and 19 in relation to the annelation of the A and B rings are discussed.