In order to obtain an optically-active β-(2-thiazolyl)-β-alanine, N-acyl-L-aspartic α- thionamide-β-methyl ester was condensed with diethyl bromoacetal, but the amino acid thus obtained showed no perceptible optical activity. The racemic amino acid, however, could be resolved into its antipodes by treating its phthalyl derivative with brucine. Thus, the (+)-amino acid, a constituent of bottromycin, was isolated in a pure state; it was determined to belong ...