Convergent synthesis of a fluorescence-quenched glycopeptide as a potential substrate for peptide: N-glycosidases

The fluorescence-quenched glycopeptide Nγ-[2-acetamido-6-(2′-amino)benzamido-2,6-dideoxy-β-d-glucopyranosyl]-Nα-benzoyl-Asn-Tyr(NO2)-OMe, having anthranilamide/3-nitrotyrosine as the donor/acceptor pair, was synthesized via a convergent route involving the EEDQ-mediated coupling of 2-acetamido-2,3-di-O-acetyl-6-(2′-tert-butoxycarbonylamino)benzamido-2,6-dideoxy-β-d-glucopyranosylamine with N-benzoyl-Asp-Tyr(NO2)-OMe, followed by deprotection.