Collect. Czech. Chem. Commun. 1987, 52, 1803-1810

Preparation of (20E)-21-methoxycarbonyl-5,14,20-pregnatrien-3β-ol derivatives

Vladimír Pouzar, Ivan Černý, Pavel Drašar and Miroslav Havel

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


(20E)-21-Methoxycarbonyl-5,14,20-pregnatrien-3β-yl hydrogen butanedioate (XII) and (20E)-21-ethoxycarbonyl-5,14,20-pregnatrien-3β-yl hydrogen butanedioate (XIV) were prepared in nine steps from 3β-acetoxy-5,14-pregnadien-20-one (I). In the key intermediate, 20-(bis(4-methoxyphenyl)phenylmethoxy)-21-nor-5,14-pregnadien-3β-yl 2-(trimethylsilyl)ethyl butanedioate (VIII), the hydroxyl in position 20 was protected with 4,4'-dimethoxytrityl group and the succinate moiety with 2-(trimethylsilyl)ethyl group.