Thermal decomposition of anomeric glycopyranosides

Abstract

Thermal analysis studies coupled with chemical studies indicate that glycopyranosides undergo thermal decomposition in two overlapping stages. The initial reaction of the glycosides at temperature between 200 and 300°C is cleavage and volatilization of the glycosidic group as the corresponding alcohol, followed by intra- or inter-molecular condensation of the glycosyl portion of the molecule. At higher temperatures (310–340°C) the major reaction is fragmentation of the carbohydrate into a variety of low molecular-weight compounds. Studies with a series of anomeric methyl and phenyl glycosides indicate that, with the methyl and phenyl glycosides, the rate of the low-temperature condensation reaction was dependent on anomeric configuration of the starting glycoside.