A series of N-protected di-and tripeptides containing the dehydroalanine unit has been prepared from the corre-sponding serine-containing peptides by a sequence of chlorination, using phosphorus pentachloride in chloroform, followed by base-catalyzed elimination. In two instances where N-benzyloxycarbonyl-L-phenylalanine was the N-terminal unit of a tripeptide, oxazoline hydrochlorides were obtained in the chlorination step. The ...
