SYNTHESE EINES TRISACCHARIDES AUS N-ACETYLNEURAMINSAEURE UND N-ACETYLLACTOSAMIN

Article abstract of DOI:10.1016/0008-6215(84)85141-1

The reaction of methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-2-chloro-2,3,5-trideoxy-D-glycero-β-D-galacto-2-nonulopyranosonate with benzyl 2-azido-3,6-di-O-benzyl-2-deoxy-4-O-(2,3-di-O-benzyl-β-D-galactopyranosyl)-β-D-glucopyranoside in the presence of mercury cyanide-mercuri bromide gave a 1:1 mixture of the two anomeric (2->6)linked trisaccharides containing N-acetylneuraminic acid.By chromatography, 22percent of benzyl O-(methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-α-D-galacto-2-nonulopyranosylonate)-(2->6)-O-(2,3-di-O-benzyl-β-D-galactopyranosyl)-(1->4)-2-azido-3,6-di-O-benzyl-2-deoxy-β-D-glucopyranoside and 23percent of the corresponding β-(2->6)-linked isomer could be isolated.A deblocking sequence, consisting of hydrogen sulfide reduction, acetylation, deacetylation, ester hydrolysis and hydrogenolysis led to the deblocked O-(5-acetamido-3,5-dideoxy-D-glycero-α-D-galacto-2-nonulopyranosylonic acid)-(2->6)-O-β-D-galactopyranosyl-(1->4)-2-acetamido-2-deoxy-D-glucopyranose and to the corresponding β-(2->6)-linked compound.