A catalytic asymmetric synthesis of N-boc-β-methylphenylalanines

摘要

An efficient, tereodivergent, and enantioselective synthesis of the syn and anti diastereomers of N-Bic-β-methylphenylalanine has been developed. Starting from enantiomerically pure (2S, 3S)- 2,3-epoxy-3-phenyl-1-propanol, a three-step sequence, consisting of the oxidation of the primary alcohol up to the carboxyl stage, ring opening of the epoxy acid with Me_2CuCNLi_2, and esterification of the resulting hydroxy acid with methyl iodide, leads to the hydroxy ester anti-10, which has been converted in a stereoduvergent manner into both the (2S,3R) and the (2R,3R) diastereomers of N-Boc-β-methylphenylalanine, syn-1 and anti-1, respectively.