Preparation of Building Blocks for Glycopeptide Synthesis by Glycosylation of Fmoc Amino Acids Having Unprotected Carboxyl Groups

Article abstract of DOI:10.1016/0040-4020(95)00224-V

N^α-Fmoc amino acids with an unprotected α-carboxyl group have been glycosylated with carbohydrate 1,2-trans peracetates using Lewis acids as promoters.Aliphatic and phenolic O- and S-glycosides of amino acids, with a 1,2-trans anomeric configuration, were obtained as products in 34-65percent yields.The glycosylated building blocks have the protective groups of choice (i.e.O-acetyl and N^α-Fmoc) for direct use in stepwise synthesis of glycopeptides.The starting materials are readily available and the method does not require an extensive experience in synthetic carbohydrate chemistry.