Synthesis and some reactions of 6-bromoandrogens: Potential affinity ligand and inactivation of estrogen synthetase

Article abstract of DOI:10.1016/0039-128X(79)90085-0

The synthesis of epimeric 6-bromo-4-androstene-3,17-dione (1a and 1b), 6-bromotestosterone (2a and 2b) and its acetate (3a and 3b), and 6-bromo-16α-acetoxy-4-androstene-3,17-dione (5a and 5b), and 6β-bromo-16α-hydroxy-4-androstene-3,17-dione (4) is described. The interconversions among compounds 1, 2, and 3 are also studied. The 6β-isomer (1b, 2b, and 3b) was epimerized to the 6α-isomer (1a, 2a and 3a) in carbon tetrachloride or chloroform-methanol (9:1) and the 6α-isomer was isolated by fractional crystallization from the epimeric mixture. 6α-Bromo isomer 1a was also epimerized back to 6β-bromo isomer 1b in chloroform-methanol (9:1). Two polymorphic forms of 6β-bromotestosterone acetate (3b) were isolated (mp. 114-117° and 138-141°). The 6β-bromo isomers were found to be unstable in methanol and decomposed to give 5α-androstane-3,6-dione derivative (6). The results of irreversible inactivation of human placental androgen aromatase with some of these 6-bromoandrogens are discussed.