N.m.r. and conformational studies of some 1,4-linked disaccharides

Abstract

¹ H and ¹³C N.m.r. studies and conformational analysis have been performed on eight 1,4-linked disaccharides in which the glycosidic linkages are in different stereochemical environments. The disaccharide glycosides have been divided into two groups, one containing α-DD-, β-LD-, and β-DL-glycosides, and one containing β-DD-, α-LD-, and α-DL-glycosides with typical chemical shift differences for each group. The conformational analysis, using the HSEA-approach, indicates a number of proton–oxygen and proton–proton interactions resulting in downfield and upfield shifts of the proton signals, respectively. The ¹³C n.m.r. glycosylation shifts obtained have been used to simulate spectra of polysaccharides containing 1,4-linkages.