Asymmetric Synthesis of β-Substituted α-Methyl-β-amino Esters by Mannich Reaction of (S,S)-(+)-Pseudoephedrine Acetamide Derived Enolate with Imines

Abstract

The reaction of an (S,S)-(+)-pseudoephedrine acetamide based enolate with several imines afforded smoothly and with full stereochemical control a series of β-substituted α-methyl-β-aminoamides that upon hydrolysis/esterification afforded the corresponding β-aminoester derivatives in good yields and in almost enantiomerically pure form.