ChemInform Abstract: Amino Acids. Part 12. Syntheses of D,L‐Cysteines from Acrylic Acid Derivatives.

Abstract

ChemInform Abstract The addition of sulfenyl chlorides such as (I) to the acrylate (II) gives mixtures of esters such as (III) and (IV) whereas addition of thiols (V) to the chloropropenate (VI) provides (III) exclusively. The dependence of the isomerization of (III) to (IV) on the reaction conditions is investigated; at higher temp., the formation of (IV) is especially favored. Reaction of (III) with NaN3 (VII) affords the azido esters (VIII) which give the cysteine derivatives (IX) of (X) under appropriate reduction conditions. D,L-Cysteine is obtained in good yield as hydrochloride hydrate (XIV) by HCl-catalyzed hydrolysis of the thiazoline (XIII).