Abstract
From 5α-cholestane-3α, 24 (R)- or -3α, 24 (S)-diol (2a and 2b) obtained from lithocholic acid in the previous work, both 24-epimers of 1α, 24-dihydroxycholesterol (6a and 6b) were synthesized. Thus, syntheses of these compounds were accomplished by dehydrogenation of the diols with dichlorodicyanobenzoquinone followed by the 1α-hydroxylation of the resulted 1, 4-dien-3-ones (3a and 3b) by the three-step procedure originally uncovered by one of the present authors (C. K.). The last step in the above transformation, the modified procedure reported recently by Ikekawa's group : oxymercuration-demercuration, was used. An alternative preparation of 1α, 24ξ-dihydroxycholesterol (6) either from lithocholic acid or from hyodeoxycholic acid was also described.
