The synthesis of 6- O-(2-acetamido-2-deoxy-β- D-glucopyranosyluronic acid)- D-glucose

Abstract

Two routes for the synthesis of 6- O-(2-acetamido-2-deoxy-β- D-glucopyranosyluronic acid)- D-glucose ( 12) were studied. In the first, benzyl 6- O-(2-acetamido-2-deoxy-β- D-glucopyranosyl)-β- D-glucopyranoside ( 10) was obtained by condensation of benzyl 2,3,4-tri- O-acetyl-β- D-glucopyranoside (obtained via the 6- O-trityl derivative) with 3,4,6-tri- O-acetyl-2-deoxy-2-diphenylphosphorylamino-α- D-glucopyranosyl bromide, followed by removal of the diphenylphosphoryl and O-acetyl groups and ▪ subsequent N-acetylation. In the second route, 2-methyl-4,5-(3,4,6-tri- O-acetyl-2-deoxy-α- D-glucopyrano)-2-oxazoline was used as 2-acetamido-2-deoxy- D-glucose moiety in the condensation reaction to give benzyl 6- O-(2-acetamido-3,4,6-tri- O-acetyl-2-deoxy-β- D-glucopyranosyl)-2,3,4-tri- O-acetyl-β- D-glucopyranoside ( 11), and subsequent removal of O-acetyl groups gave compound 10. Oxidation of the primary hydroxyl group of 10 gave benzyl 6- O-(2-acetamido-2-deoxy-β- D-glucopyranosyluronic acid)-β- D-glucopyranoside ( 8), which was converted by catalytic hydrogenolysis into the free disaccharide 12.