The pyrolysis of some hexoses and derived di-, tri-, and poly-saccharides

Abstract

The vacuum pyrolysis of glucose, galactose, mannose, fructose, and certain derived di-, tri-, and poly-saccharides gives, as major products, 1,6-anhydrohexo-pyranoses and -furanoses and 5-hydroxymethylfurfuraldehyde. These, together with some minor products, have been estimated as the O-trimethylsilyl ethers by gas chromatography. The pyrolytic reactions, which in many respects resemble acid-catalysed reactions in aqueous solution, are discussed, particularly in relation to the influence of thermally induced conformational changes. Glucose is shown to undergo mutarotation and condensation–polymerisation in the molten state; the pyrolysis products are those of the resulting polymer.