SYNTHESIS OF HYDRINDAN DERIVATIVES RELATED TO VITAMIN-D

Two independent routes to the CD fragment of vitamin D metabolites and analogues are described. The trans-hydrindanol 4 was synthesized from enedione 5. The key step in this synthesis was the hydroxyl-directed hydrogenation of hydrindenols of type 15 in the presence of Wilkinson's catalyst. The trans-hydrindanone 6 was efficiently prepared by degradation of the Lythgoe-Inhoffen diol (3). Both 4 and 6 are suitable precursors for the preparation of new potentially useful analogues of 1-alpha,25-dihydroxyvitamin D3 that are functionalized at C20, C21, or ring D.