Aliphatic and cyclic ketones are smoothly reduced to give corresponding alcohols in high yields with 10 equivalent magnesium metal in absolute ethanol in the presence of a catalytic amount of HgCl2 at room temperature. In the case of 2-substituted cyclic ketones, trans isomers are obtained as major adducts because of steric effect. Comparing to cyclic pentanones and cyclic hexanones, cyclic butanones are more easily reduced because of ring strain.
( 그림 삽입 )
This method can be safe, efficient, economic and complementary to Na and K.