Synthesis of some oligosaccharides with D-galacto- and D-gluco-configuration and reductive opening of carbo-hydrate acetals

Abstract: Syntheses of the following oligosaccharides, required for immunological studies. are discussed: £-trifluoroacetamidophenyl O-a-D-glucopyranosyl-(1+4)-a-D-galactopyranoside, ß-trifluoroacetamidophenyl O-a-D-glucopyranosyl-(1 + 6)-a-D-galactopyranoside, 8-methoxy- carbonyloct-1-yl 0-a-D-galactopyranosyl-(1+3)-fi-ß~9"9alact°Pyranosyl- (1+4)-2-acetamido-2-deoxy-ß-D-glucopyranoside, methyl û-a-D-fuco- pyranosyl-(1+4)-ß-D-galactopyranoside, methyl û-a-D-galactopyranosyl- (1+4)-ß-D-fucopyranoside and methyl ß-a-D-fucopyranosyl-(1+4)-ß-D- fucopyranoside. A synthesis of a sucrose derivative suitable for selective acylation at OH-2, OH-3 and/or OH-4 is also described. Furthermore, reductive opening of acrolein acetals with sodium cyanoborohydride/hydrogen chloride and of benzylidene acetals with borane trimethylamine/aluminium chloride is examined. The dependency of regioselectivity on solvent and reagents is investigated.