The chemical synthesis of polysaccharides. Part I. Synthesis of gentiodextrins

When treated with silver oxide in chloroform, 2 : 3 : 4-tri-O-acetyl- α-D-glucopyranosyl bromide polymerises with elimination of hydrogen bromide. The products are O-acetyl derivatives of levoglucosan and the series of gentiodextrins, i.e., β-glucopyranose polymers based on the repeating 1: 6-linkage. Molecules containing up to nine glucose units have been detected and the deacetylated products have been characterised by measurement of physical properties and formation of crystalline O-acetyl derivatives. Glucose and, probably, cellobiose and ββ-trehalose are also formed. The potentialities of this type of polymerisation are considered.