Preparation of B-ring brominated derivatives of estradiol.

Article abstract of DOI:10.1016/0039-128X(86)90025-5

The preparation of 6 beta-methoxy-7 alpha-bromoestradiol (1) is reported. Addition of in situ-generated BrOMe to 6-dehydroestradiol 3-tetrahydropyranyl ether (4a) afforded the expected addition product. Removal of the tetrahydropyranyl protective group was carried out by mild acid hydrolysis to afford 1 in good yields. This base-sensitive compound is chemically stable over long periods of time.