Molécules modèles des motifs des poly-1,4-glucosides. I. Synthèse et correspondance configurationelle de diastéréoisomères avec les motifs de la cellulose et de l'amylose

Abstract

To confirm or to elucidate the most probable types of chelation existing in the chains of cellulose or amylose as well as in the corresponding mono- and disaccharides, we have undertaken studies on model molecules which represent, in part, the cellobiose and maltose entities. These model molecules are some intra- extra cyclic acetals of the type 2-cyclohexytoxytetrahydropyran. These molecules contain primary or secondary hydroxyl groups whose covalent dispositions relative to the acetal function are analogous to those of the groups (OH)2, (OH)3′, (OH)6, and (OH)6′, of amylose and cellulose. Twenty-one model compounds have been pre-pared from 2,3-dihydropyran, 2-hydroxymethyl-2,3-dihydropyran, or their expoxides. Most of the diastereoisomers corresponding to the model compounds containing at least two asymmetric carbon atoms have been separated by gel permeation chromatography using a recycling system to some advantage. The configurational correspondence of the diastereoisomers to the entities α-D- and β-D-glucose of amylose and of cellulose have been studied by proton and carbon-13 nuclear magnetic resonance. These assignments have permitted the recognition, among the 30 diastereoisomers of 6 which have the configuration of amylose and of 5 which have that of cellulose. [Journal translation]