The synthesis of a chiral ?-amino acid derivative by the Grignard reaction of an aspartic acid equivalent

A novel synthetic route to chiral ?-amino acid derivative has been developed by a Grignard reaction of 2,4,5-trifluorophenyl magnesium bromide with the Weinreb amide derivative of L-aspartic acid. The aspartic equivalent was synthesised from L-aspartic acid in four steps, and the Grignard reagent was prepared by Br-Mg-exchange reaction. The target compound was achieved after the Grignard reaction and a subsequent reduction. Tthe stereo structure of the chiral amine was well preserved from the L-aspartic acid.