From methyl D-glucopyranoside to methyl D-allopyranoside via the Mitsunobu reaction

摘要

Methyl #beta#-D-glucopyranoside reacted with a 4-molar excess of the Mitsunobu reagents (triphenylphosphine-diethyl azodicarboxylate-benzoic acid) under Weinges et al. [Carbohydr. Res., 164 (1987) 453-458] conditions to furnish four differently benzoylated methyl #beta#-D-allopyranosides in a very good overall yield. The same reaction applied to methyl #alpha#-D-glucopyranoside yielded allosides in a low yield and nine other sugar products. These results give an insight into the course of the Mitsunobu esterification-inversion reaction.