Convenient Synthetic Route to an Enantiomerically Pure FMOC α-Amino Acid

A strategy for the facile α-amination of carboxylic acid menthyl esters is described. The resulting diastereomers, readily separable, can be individually carried on to each enantiomer of the FMOC α-amino acid. A variety of unnatural side chains were compatible with this approach. The menthyl ester was easily removed from the FMOC α-amino acid without racemization.