Conversion of carbonyl steroid derivatives to 1,1-dibromoalkenes by the catalytic olefination reaction and synthesis of functionally substituted steroids on their basis

Catalytic olefination of carbonyl steroid derivatives were used to obtain the corresponding 1,1-dibromoalkenes. For this, N -unsubstituted steroid hydrazones were involved into the reaction with tetrabromomethane in the presence of copper( i ) chloride. The dibromides can be used for the synthesis of various functionalized steroids by conversion of a dibromomethylidene fragment to the carboxy, amide, and phosphonate groups.