STEREOSELECTIVE AZA-HENRY REACTION OF CHIRAL tert-BUTANESULFINYL IMINES WITH METHYL OR ETHYL 4-NITROBUTANOATE : EASY ACCESS TO ENANTIOENRICHED 6-SUBSTITUTED PIPERIDINE-2,5-DIONES (Dedicated to Professor Isao Kuwajima on the occasion of his 77th birthday)

Abstract

Base-catalyzed addition of 4-nitrobutanoates to chiral aldimines (II) proceeds with high facial selectivity (84—96%) furnishing the β-nitroamine derivatives (III), which can be easily converted into enantioenriched 6-substituted piperidinediones (VI).