The reduction of the ketone to a secondary alcohol that accompanies addition in reactions of ketones and dialkylmagnesium compounds can be lessened by first adding an appropriate salt to the dialkylmagnesium compound. With favorable salts and reactant stoichiometries, reduction is eliminated in reactions of dipropylmagnesium with diisopropyl ketone or di-tert-butyl ketone. In reactions of di-tert-butylmagnesium and di-tert-butyl ketone, reduction always predominates, although some addition does occur. Salts observed to have significant effects are potassium methoxide, (Me 2 NCH 2 ) 2 CHOK, sodium methoxide, lithium methoxide, lithium tert-butoxide, tetrabutylammonium bromide, and benzyltriethylammonium chloride