Two general methods have been used for the synthesis of a-halogen-a,@-unsaturated ketones. In the first method'halogen is added to an al/3-unsaturated ketone and hydrogen halide is then removed with the aid of a basic agent such as sodium alcoholate, alcoholic alkali, alkali acetate, or pyridine. This procedure has been used successfully with the relatively stable unsaturated ketones of the aromatic series such as benzal acetone and ...
