Enantioselective Syntheses of (<i>R</i>)‐Amino Acids Using <scp>L</scp>‐Valine as Chiral Agent

Abstract

(R)-Amino Acids can be synthesized via the cyclic bislactim ethers (dihydropyrazines) of cyclo-(L-Val-Gly), by successive metalation, alkylation, and hydrolysis, in good yields and in high optical purity. They are e.g. of importance as enzyme inhibitors. Presumably the reaction proceeds via the planar dihydropyrazine anion (1).