Hydrozirconation of four-, five-, six- and seven-membered N-alkoxycarbonyl lactams to lactamols

A general, practical, and efficient reduction of four-, five-, six- and, seven-membered N-alkoxycarbonyl lactams to the aldehyde oxidation state is reported. The reduction methodology involves the hydrozirconation reaction by Cp2Zr(H)Cl under mild conditions and proceeds with very short reaction times and in excellent to good yields. The hydrozirconation of N-alkoxycarbonyl lactams with the Schwartz reagent demonstrated to be the mildest and most general method for the formation of lactamols with a high functional group tolerance.