The alkylation of menthyl hippurate and some related materials: a reinvestigation

Benzylation of chiral esters of N-acylglycines using various bases and additives was examined. No C-alkylation was observed with one equivalent of base. Diastereoselectivities were dependent on the amount of additive, the nature of the N-acyl group, and the chiral ester. A model to account for the degree and sense of the stereoselectivity is proposed.