10.1021/jo01347a030
The study explores the conversion of L-p-chloroalanine peptides to L-cysteine peptides using thio reagents such as thioacetate, thiobenzoate, and benzyl mercaptide in solvents like N,N-dimethylformamide or ethyl acetate. The researchers synthesized several di-, tri-, and penta-1-cysteine peptides through this method. The study also investigates the reaction of thio reagents with L-p-chloroalanine peptides, resulting in the formation of optically active L-cysteine peptides. The displacement of p-chloro groups by thioacetic acid was extended to peptides with the chloroalanine moiety between other amino acid residues in tripeptides and pentapeptides. The study provides detailed experimental procedures and analytical data for the synthesized compounds.