Mutarotation of α-D-glucose catalysed by pyridine-phenols and pyridine-water catalyst pairs in dimethylformamide

Abstract

The rate of mutarotation of α-D-glucose is at a maximum for close to 1 : 1 molar composition of acid and base catalysts when pyridine-phenol, pyridine-p-cresol and pyridine-p-chlorophenol catalyst pairs are used in dimethylformamide solutions at 34.6°C. The evidence favours a termolecular bi-functional catalytic mechanism. No rate maximum is detectable for the pyridine-water catalyst pair under the same conditions. Two water molecules appear to be operative at the rate- determining step in dilute dimethylformamide solution.