Base promoted chemoselective reduction of α‐keto amides and α‐keto esters with TsNHNH2

A method for chemoselective reduction of α‐keto amides and α‐keto esters using tosylhydrazine in the presence of NaHCO3 has been developed. A variety of α‐hydroxy amides and α‐hydroxy esters were obtained in good to excellent yields, demonstrating the efficiency of the present protocol. A possible reaction mechanism is proposed based on the deuterium‐labelling experiments.