Chemical synthesis of β-d-psicofuranosyl disaccharides Original Research Article

Disaccharides composed of a β-d-psicofuranosyl unit were prepared by the glycosylation reaction of monosaccharide acceptors including three 2,3,4,6-tetra-O-protected hexopyranoses with a d-psicofuranosyl benzyl phthalate derivative (4). A β-d-psicofuranosidic bond was formed by the TMSOTf-promoted reaction with high selectivity. Removal of the O-protecting groups from the resulting α-d-hexopyranosyl β-d-psicofuranosides furnished the first chemical synthesis of α-d-gluco-, α-d-galacto-, and α-d-mannopyranosyl β-d-psicofuranosides. The common β-d-psicofuranosyl donor 4 was derived efficiently from d-psicose in five steps.