Silver trifluoromethanesulphonate as an S-deprotecting reagent for the synthesis of cystine peptides

Abstract

The acetamidomethyl (Acm) group attached at the thiol function of cysteine was found to be cleaved quantitatively by treatment with silver trifluoromethanesulphonate in trifluoroacetic acid, this reagent being more effective than silver trifluoroacetate and cleaved the S-benzamidomethyl and the S-p-methoxybenzyl groups as well; this new S-deprotecting reagent has been used in the synthesis of oxytocin and chicken calcitonin.