Bromine → 21-Bromo-3alpha-hydroxy-5beta-pregnane-11,20-dione

Participants

Reaction Steps

A stirred solution of 3α-hydroxy-5β-pregnane-11,20-dione (10 g.) in dry methanol (700 ml.) was treated at 0° with a solution of bromine (1.9 ml.) in methanol (45 ml.) at such a rate that the yellow colour disappeared before further addition. The solution was then partitioned between water and chloroform. The organic layer was washed with water, dried (Na2SO4) and evaporated. Chromatography of the residue (with benzene/ethyl acetate, 2.5:1) gave title compound (7.2 g.) as a white foam; [α]D + 100°(c 1.1).

Provenance & Evidence