A. Lubineau, C. Augé, Bénédicte Bouxom
1992
Citations
0
Influential Citations
6
Citations
Journal
Journal of Carbohydrate Chemistry
Abstract
Abstract Benzyl 2-acetamido-2-deoxy-4,6-O-(4-methoxybenzylidene)-β-D-glucopyrano-side (3) was glycosylated with 2,3,4,6-tetra-O-acetyl-α-D-galactopyranosyl bromide (2) to give disaccharide 4. Reductive ring-opening of the acetal group provided as a major compound (64%) the 6-O-(4-methoxybenzyl) derivative (5) which was directly converted into benzyl 2-acetamido-3-O-(2,3,4,6-tetra-O-acetyl-β-D-galactopyranosyl)-4-O-benzoyl-2-deoxy-β-D-galactopyranoside (10) through triflate displacement by tetra-n-butylammonium benzoate, followed by removal of the 4-methoxybenzyl ether group. The minor compound (30%) (6) could be also converted into 10 through the 6-O-(tert-butyldimethylsilyl) ether 8 which was treated similarly to compound 5. Stannous triflate promoted condensation of methyl (5-acetamido 4,7,8,9-tetra-O-acetyl-2,3,5-trideoxy-D-glycero-β-D-galacto-2-nonulopyranosyl chloride)onate (12) with the glycosyl acceptor 10, in tetrahydrofuran, afforded a 3:1 mixture of a and β (2→6) linked trisaccharides 13 and 14 ...