PRODUCTION OF VITAMIN D3 DERIVATIVE

摘要

PROBLEM TO BE SOLVED: To simply produce a mass-producible vitamin D3 derivative in good yield by using a hydroxyvitamin D3 derivative available in a large amount as a starting raw material. SOLUTION: A compound of formula I ]R<1> is an alkyl or OR<5> (R<5> is H or a protecting group of hydroxyl group), a halogen, a hydroxyalkyl or a halogenated alkyl; R<1> and R<2> are each independently an alkyl, OR<6> (R<6> is a protecting group of hydroxyl group), a halogen, etc.; R<4> is H, an alkyl, OR<5> , a halogen, etc.; U, W, X, Y and Z are each independently (S=O), O, etc.] is oxidized to afford a vitamin D<3> derivative of formula II. Furthermore, the resultant derivative of formula II is silyl-enol-etherified with an enolizing agent and a silylating agent and oxidized with a peracid. The deprotecting reaction of the resultant compound is subsequently carried out to provide a vitamin D3 derivative of formula III (OR<5> is only hydroxyl group; when any one of U, W, X, Y and Z is hydroxyl group, the hydroxyl group is not protected).