Direct glycosylation of protected O-tritylserine esters and oligopeptides
摘要:
N-Finoc-3-O-Tr-L-serine methyl and benzyl esters, as well as a tripeptide FmocAlaSeI(Tr)GlyOBn were directly glycosylated by 3,4,6-tri-O-acetyl-1,2-O-(1-cyanoethylidene)-alpha-D-galactopyranose in the presence of TrClO(4) in dichloromethane, yielding 32-57% of N-Fmoc-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-L-serine esters and the corresponding tripeptide.