Clemmensen reduction. Part IV. 1,4-Diketones

Abstract

Clemmensen reduction of 1,4-diketones proceeds by a variety of pathways. Saturated and unsaturated alcohols are the major products from hexane-2,5-dione but some products of reductive cleavage are also formed. Synthesis of trans-1,2-dimethylcyclobutane-1,2-diol shows that this is a minor intermediate in this reduction. Reductive cleavage is predominant with cyclohexane-1,4-dione, but was not detected for a steroidal diketone. When one of the carbonyl groups is conjugated with an aromatic ring, normal reduction occurs.