N-Methyl Pseudoephedrine-mediated Asymmetric Syntheses of Dihydroquinoxalinones for the Preparation of Flavane Analogues

摘要

N-Methyl pseudoephedrine mediated asymmetric nucleophilic substitution of alpha-bromo esters has recently been developed in our laboratory for stereoselective preparation of alpha-amino,alpha-mercapto and alpha-hydroxy carboxylic acids.The successful results on dynamic resolution of N-methyl pseudoephedrine alpha-bromo esters prompt us to extend the methodology to asymmetric syntheses of 3-substituted dihydroquinoxalinone derivatives.