“On-water” reduction of α-keto amide by Hantzsch ester: A chemoselective catalyst- and additive-free way to α-hydroxy amide

An efficient and practical method for chemoselective “on-water” reduction of α-keto amide by Hantzsch ester without using any catalysts and additives was developed. Control experiments indicated that the intramolecular hydrogen bond of α-keto amide was crucial for this transformation. A variety of α-hydroxy amides were prepared in high yields in an environmentally friendly way.