Glycosylation of N-acetylglucosamine: imidate formation and unexpected conformation.
[structure: see text] Rhamnosylation in mild conditions of a disaccharide containing N-acetylglucosamine afforded the imidate 6 while at higher temperature and concentration of promoter trisaccharide 7 was isolated. The kinetic imidate 6 was independently rearranged in 50% yield to the thermodynamic trisaccharide 7. Comparative NMR studies of 7 in CDCl(3) and DMSO-d(6) suggest the formation of a nonchair conformation in CDCl(3). The structure of 7 was confirmed through the independent synthesis of the N-acetylacetamido trisaccharide 11.
Liao
Liang
L
Department of Chemistry and Biochemistry, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Auzanneau
France-Isabelle
FI
D000117:Acetylglucosamine / Q000737:chemistry* / Q000378:metabolism; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D006031:Glycosylation; D007096:Imidoesters / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D012210:Rhamnose / Q000031:analogs & derivatives
D007096:Imidoesters; D012210:Rhamnose; D000117:Acetylglucosamine