A comparative study of the influence of some protecting groups on the reactivity of D-glucosamine acceptors with a galactofuranosyl donor.
Competitive glycosylation experiments with a galactofuranosyl trichloroacetimidate donor were performed with glucosamine acceptors having a free 4-OH group and carrying different protecting groups at N-2, O-3, and O-6. The most reactive acceptor is the N-dimethylmaleimido 3,6-di-O-benzylated derivative (6c), which reacts even faster than the oxazolidinone 1a. Molecular orbital calculations have helped to rationalize these experimental facts in terms of a hard-hard reaction occurring between the donor and the acceptor.
Bohn
María L
ML
Instituto de Química Orgánica y de Síntesis (CONICET-UNR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Suipacha 531, 2000 Rosario, Argentina.
Colombo
María I
MI
Stortz
Carlos A
CA
Rúveda
Edmundo A
EA
D005690:Galactose / Q000737:chemistry*; D005944:Glucosamine / Q000737:chemistry*; D006031:Glycosylation
D005944:Glucosamine; D005690:Galactose