Stereoselective synthesis of S-norvaline and related amino acids through a common intermediate

Abstract

A divergent, enantioselective synthetic strategy is reported to produce the non-proteinogenic, biologically active natural amino acids norvaline, 5-hydroxy-4-oxo-L-norvaline, and ɣ-oxonorvaline. These were synthesized in good yields (45-75%) from the common starting material (S)-allylglycine obtained by asymmetric transfer allylation of glycine Schiff base using the Corey catalyst derived from cinchonidine in more than 97% enantiomeric excess.

Keywords: 5-Hydroxy-4-oxo-S-norvaline; Allylglycine; Amino acid; Norvaline; Phase transfer catalysis; ɣ-oxonorvaline.