A Highly Chemoselective Reduction of Conjugated Nitro Olefins with Hantzsch Ester in the Presence of Silica Gel

An effective system to reduce conjugated nitro olefins into the corresponding nitroalkanes is described. The system composed of Hantzsch ester (HEH) and silica gel in benzene exerts high yield and excellent chemoselectivity under almost neutral conditions. Facile applications of the system to the syntheses of natural products are also described.