Redox glycosidation: stereoselective syntheses of (1.fwdarw.6) linked disaccharides via thionoester intermediates
摘要:
Perbenzyl derivatives of the disaccharides benzyl 6-O-(alpha(and beta)-D-glucopyranosyl)-alpha-D-galactopyranoside and benzyl 6-O-(alpha(and beta)-D-mannopyranosyl)-alpha-D-galactopyranoside were each prepared in a stereoselective manner by acylation, thionation, and reductive desulfurization. The use of 2,4-bis(4-phenoxyphenyl)-1,3,2,4-dithiadiphosphetane 2,4-disulfide (4b) as a mild thionation reagent for esters and lactones is also described.
A new approach to the synthesis of disaccharide derivatives having a furanose as the reducing unit
作者:Cecile du Mortier、Oscar Varela、Rosa M. de Lederkremer
DOI:10.1016/0008-6215(89)84087-x
日期:1989.6
The lactonic disaccharide 2,3,5-tri- O -benzoyl-6- O -(2,3,4,6-tetra- O -acetyl-β- d -glucopyranosyl)- d -galactono-1,4-lactone ( 7 ) was prepared by condensing 6- O -trityl-2,3,5-tri- O -benzoyl- d -galactono-1,4-lactone ( 2 ) with 2,3,4,6-tetra- O -acetyl-α- d -glucopyranosyl bromide ( 4 ) or with 1,2,3,4,6-penta- O -acetyl-β- d -glucopyranose ( 6 ). The reaction was carried out using various catalysts