Synthetic studies of vitamin D3 analogues from bile acids. Part 3. Syntheses of 1α,25-, 1α,24R-, and 1α,24S-dihydroxycholecalciferols from lithocholic acid and their biological activities

Abstract

Syntheses of 1α,25-, 1α,24R-, and 1α,24S-dihydroxycholecalciferols from lithocholic acid via the analogous 1,4,6-trien-3-ones by application of Kaneko's procedure are described. A new synthesis of 1α,25-dihydroxycholecalciferol from lithocholic acid via the 1,4-dien-3-one is also reported. The biological activities of the three cholecalciferols were tested.