A new approach for the synthesis of tyrosine sulphate containing peptides: use of the p-(methylsulphinyl)benzyl group as a key protecting group of serine
A convenient method for the synthesis of tyrosinesulphate [Tyr(SO3H)] containingpeptides, using Fmoc–solid-phase strategy (Fmoc = fluoren-9-ylmethoxycarbonyl) for peptide-chain construction and O-p-(methylsulphinyl)benzylserine for the selective sulphation of tyrosine, has been developed and cholecystokinin (CCK)-12 synthesized as a model peptide.