Preparations of Optically Active Homocysteine and Homocystine by Asymmetric Transformation of (RS)-1,3-Thiazane-4-carboxylic Acid

Article abstract of DOI:10.1246/bcsj.66.536

DL-Homocysteine from (RS)-homocysteine thiolactone hydrochloride <(RS)-HTL*HCl> was subjected to reaction with formaldehyde in acetic acid to give (RS)-1,3-thiazane-4-carboxylic acid monohydrate <(RS)-THA*H2O>.An asymmetric transformation of (RS)-THA*H2O was achieved via salt formation with optically active tartaric acid in the presence of salicylaldehyde in acetic acid.The (R)- and (S)-THA obtained, respectively, from the salt of (R)-THA with (2R,3R)-tartaric acid and its enantiomeric salt were treated with hydroxylamine hydrochloride to give D- and L-Hcy of 100percent optical purity, respectively, in 50percent yield from (RS)-HTL*HCl.Oxidation of D- and L-Hcy with hydrogen peroxide gave D- and L-homocystine, respectively, in 47percent yield.