Straightforward entry to s-glycosylated fmoc-amino acids and their application to solid phase synthesis of glycopeptides and glycopeptidomimetics

Streamlined access to S-glycosylated Fmocamino acids was developed. The process provides diverse glycosylated modified amino acids in high yield and stereoselectivity taking advantage of the in situ generation of a glycosylthiolate obtained from carbohydrate acetates in a few steps. Mild basic conditions make the conjugation reaction compatible with Fmoc-iodo-amino acids. To validate the strategy the glycosylated building blocks were used for SPPS and the unprecedented incorporation of a long thiooligosaccharide to the peptide chain was demonstrated.