Enantioselective synthesis of (S)- and (R)-alpha-methylserines: application to the synthesis of (S)- and (R)-N-Boc-N,O-isopropylidene-alpha-methylserinals

This report describes the synthesis of enantiomerically pure (S)- and (R)-a lpha -methylserines on a multigram scale, starting from the Weinreb amide o f 2-methyl-2-propenoic acid and using a stereodivergent synthetic route tha t involves a Sharpless asymmetric dihydroxylation reaction. As a synthetic application of these quaternary alpha -amino acids, they were used as start ing materials in the synthesis of the well-known valuable homochiral (S)- a nd (R)-N-Boc-N,O-isopropylidene-alpha -methylserinal building blocks. (C) 2 001 Elsevier Science Ltd. All rights reserved.