Asymmetric synthesis of 3-amino-2-hydroxyalkanoates by Mannich reaction of menthyl acetate with imines and subsequent oxidation

Lithium amide-assisted Mannich-type reaction of menthyl acetate-derived lithium enolate with PMP-arylaldimines and subsequent in situ oxidation with oxaziridine gave syn-3-amino-3-aryl-2-hydroxypropanoates with high syn-selectivity and diastereoselectivity (with respect to menthyl moiety) in a one-pot procedure. Propargyl aldehyde-derived imines were also stereoselectively converted to the Mannich-oxidation products by a stepwise procedure.