Acetalation of sucrose by acetal exchange with concomitant fission of the glycosidic bond. Some new acetals of D-glucose and methyl α-D-fructofuranoside

Abstract

Prolonged reaction of sucrose with 2,2-dimethoxypropane in NN-dimethylformamide in the presence of toluene-p-sulphonic acid (0.3% w/v) afforded, after acetylation, methyl 4,6-di-O-acetyl-1,3-O-isopropylidene-α-D-fructofuranoside together with four acetals of D-glucose, namely, (1S)-1-methoxy-1,2:3,4:5,6-tri-O-isopropylidene-D-glucitol, 3-O-acetyl-1,2:5,6-di-O-isopropylidene-α-D-glucofuranose, 3-O-acetyl-1,2:4,6-di-O-isopropylidene-α-D-glucopyranose, and 1,2,3-tri-O-acetyl-4,6-O-isopropylidene-αβ-D-glucopyranose. the mechanism of formation of these compounds is discussed. Several derivatives of methyl α- and β-D-fructofuranosides have been prepared from methyl 1,3-O-isopropylidene-α-D-fructofuranoside.