A novel and practical route to A-ring enyne synthon for 1α,25-dihydroxyvitamin D3 analogs: Synthesis of A-ring diastereomert of 1α,25-dihydroxyvitamin D3 and 2-methyl-1,25-dihydroxyvitamin D3

Article abstract of DOI:10.1016/S0960-894X(97)10204-9

A novel and practical route to the A-ring enyne synthon (2), which can be versatile far a variety of A-ring analogs of 1α,25-dihydroxyvitamin D₃ (1), was developed. This novel method led to an improved synthesis of the A-ring diastereomers of 1, the compounds 13-15, and synthesis of the new analogs, 2-methyl-1,25-dihydroxyvitamin D₃ (4) with its all possible diastereomers. The biological evaluation of the 2-methyl analogs showed the ααβ-isomer to be more potent than 1.