炭水化物水酸基の相対的反応性について : メチル4,6-ο-ベンジリデン-β-D-グルコピラノシドの非プロトン性溶媒中での選択的エステル化反応

Abstract

Methyl 4,6-O-benzylidene-β-D-glucopyranoside was benzoylated with a limited a mount of benzoic anhydride in a series of aprotic solvents in the presence of sodium benzoate.Partial benzoylation of the glucoside in a cetonitril, dichloromethane, N, N-dimethylformamide and pyridine, respectively, gave the preponderance of 3-O-benzoate over 2-O-benzoate as shown by quantitative TLC, while the benzoylation in acetone gave the higher yield of 2-O-benzoate than that of 3-O-benzoate.This reverse result suggests that acetone has a certain activating solvent effect on the reactivity of HO-2 in methyl 4,6-O-benzylidene-β-D-glucopyranoside derivatives toward benzoylation with benzoic anhydride.