Collect. Czech. Chem. Commun. 1985, 50, 869-877

Preparation and absolute configuration at C(22) of 21,26,27-trinor-5α-cholestan-25→22-olide derivatives

Vladimír Pouzar, Pavel Drašar, Ivan Černý and Miroslav Havel

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


Epimeric 21,26,27-trinor-5α-cholestan-25→22-olides (X and XVII), 21,26,27-trinor-5α-cholest-23-en-25→22-olides (XV and XXII), and their 23-methyl derivatives XVI and XXIII were prepared by lengthening the side chain in 5α-pregnan-21-al (I). On the basis of CD spectra and chemical correlations with 21,26,27-trinor-5α-cholestane-22,25-diols, the configuration 22S was ascribed to lactones X, XXII and XXIII whereas lactones XV, XVI and XVII were assigned the 22R configuration.