HIGH-ACCURACY MEASUREMENT OF PROTON CHEMICAL-SHIFTS AND COUPLING-CONSTANTS IN SUBSTITUTED CYCLIC OLIGOSACCHARIDES USING PHASE-SENSITIVE 2-DIMENSIONAL SOFT EXPERIMENTS

The performances of soft COSY and RELAY experiments are demonstrated for substituted cyclic oligosaccharides. In association with soft NOESY, they allow fast sequencing of complex molecules and high-accuracy measurements of both chemical shifts and coupling constants, which are required for a complete determination of the three-dimensional structure of these compounds. These procedures are applied to a cyclodextrin derivative for which self-inclusion of the aromatic moiety in the hydrophobic cavity induces large ring current effects which can be used to derive the three-dimensional structure of this molecule. © 1991.