NOUVELLE METHODE DE SYNTHESE STEREOSELECTIVE DE GLYCOSIDES. SYNTHESE DES α,α-TREHALOSE, ANALOGUES galacto, manno ET AUTRES α-D-GLYCOSIDES

Article abstract of DOI:10.1016/S0008-6215(00)85133-2

In the presence of trifluoromethanesulfonic (triflic) anhydride as catalyst and dichloromethane as solvent, in the cold, 2,3,4,6-tetra-O-benzyl-D-glucopyranose, 2,3,4,6-tetra-O-benzyl-D-galactopyranose, and 2,3,4,6-tetra-O-benzyl-D-mannopyranose were converted in almost quantitative yield to a 2:1 mixture of the corresponding α,α-(1->1) and α,β-(1->1) disaccharides.Hence, pure 2,3,4,6,2',3',4',6'-octa-O-benzyl derivatives of α,α-trehalose, and the D-galacto and D-manno analogues were obtained, after column chromatography, in 55-65 percent yield.Hydrogenolysis gave the corresponding free sugars.The pure anomers were obtained in 10-34 percent yield.The potentiality of the method was demonstrated by the synthesis of 2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl 2,3:4,5-di-O-isopropylidene-β-D-fructopyranoside in 50 percent yield, and of N-(benzyloxycarbonyl)-3-O-(2,3,4,6-tetra-O-benzyl-α-D-glucopyranosyl)-L-threonine methyl ester in 65 percent yield.