Nucleophilic addition reactions and functionalization of (3-methoxyestrone)- and (3,17-dimethoxyestradiol)manganese tricarbonyl complexes

Nucleophilic addition of MeMgCl and PhMgBr to the A-ring aromatic steroid complex [(eta 6-3,17-dimethoxyestradiol)Mn(CO)(3)](+) gives stable eta(5)-cyclohexadienyl complexes and occurs at the C-1 site meta to the -OMe group when the metal is on the ''beta'' side of the steroid; addition to the ''alpha'' analogue is less regioselective due to steric interactions and occurs at C-1, C-2, and C-4. A manganese-mediated procedure is reported for the functionalization of estrone at the C-1 position to give 1-methylestrone in 42% yield.