Preparation of 1 alpha , 24-dihydroxyvitamin D analogs

摘要

A synthesis of 1 alpha ,24(R)- and 1 alpha ,24(S)-dihydroxy-22(E)-dehydrovitamin D3 compounds. This process involves two major operations, namely, (a) the attachment of the required side chain to an existing vitamin D-22-aldehyde derivative to obtain an enone derivative as an intermediate, and (b) the stereoselective reduction of the ketone group of said enone intermediate to obtain the desired 24(R)- and 24(S)-hydroxyvitamin D compounds. The vitamin D enone derivatives generated as intermediates in the process are also new compounds.