N.m.r. and conformational studies on some 1,3-linked disaccharides

Abstract

¹³ C and ¹H N.m.r. data have been obtained from 10 methyl 6-deoxyhexosylhexosides in which the 6-deoxysugar is the L- or D-enantiomer of fucose or rhamnose. A large variation in the magnitude of displacement shifts of signals for α- and β-carbons is observed. For all compounds Hard Sphere Exo Anomeric effect (HSEA) calculations have been performed to estimate favoured conformations. From the derived minimum energy conformations, a number of ¹H n.m.r. chemical shifts can be rationalised.