Iodine-promoted cleavage of the C-17-dihydroxyacetone side chain of corticosteroids in aqueous ammonia water

A convenient approach to 17-ketosteroids by the iodine-promoted cleavage of the C-17-dihydroxy acetone side chain of corticosteroids is described. Treatment of steroids containing the C-17-dihydroxyacetone side chain with iodine and an excess of aqueous ammonia in acetonitrile at 50 degrees C, affords high yields of the corresponding 17-ketosteroids.