Chemical regioselective hydrolysis of peracetylated reducing disaccharides, specifically at the anomeric centre: Intermediates for the synthesis of oligosaccharides
摘要:
Reaction of reducing disaccharide peracetates 1, 5, 9 and 13 with hydrazine hydrate in acetonitrile gave predominantly the corresponding heptaacetates 2, 6, 10 and 14, with the free hydroxyl group at C-l or the hexaacetates 3, 7, 11 and 12, with the hydroxyl groups at C-1,2 or C-1,3 and the pentaacetates 4 and 8 with the hydroxyl groups at C-1,2,3, depending on the quantity of reagent used.
Versatile acetylation of carbohydrate substrates with bench-top sulfonic acids and application to one-pot syntheses of peracetylated thioglycosides
作者:Chin-Sheng Chao、Min-Chun Chen、Shih-Che Lin、Kwok-Kong T. Mong
DOI:10.1016/j.carres.2008.01.014
日期:2008.4
sulfonic acids, p-toluenesulfonic acid, and sulfuric acid are versatile and efficient catalysts for the peracetylation of a broad spectrum of carbohydrate substrates in good yield and in a practical time frame. Three appealing features in sulfonic acid-catalyzed acetylation of freesugars were explored including (1) suppression of furanosyl acetate formation for D-galactose and L-fucose; (2) high yielding