INTERMEDIATES FOR THE SYNTHESIS OF VITAMIN D AND STEROID DERIVATIVES

摘要

A process for preparing a compound having structure (I) wherein n is an integer from 1-5; each of R 1 and R 2 independently is optionally substituted C 1 -C 6 alkyl; each of W and X is independently hydrogen or C 1 -C 6 alkyl; Y is O, S or NR 3 where R 3 is hydrogen, C 1 -C 6 alkyl or a protective group; and Z is a CD ring structure, a steroid structure, or a vitamin D structure, each of which optionally has one or more protected or unprotected substituents and/or one or more protective groups. This process comprises reacting a compound having structure (IV) wherein W, X, Y and Z are as defined above, in the presence of a base, with a compound having structure (V) or (V') wherein n, R 1 and R 2 are as defined above, and E is an eliminating group.