DETERMINATION OF PROTON-PROTON DISTANCES IN 2-ACETAMIDO-2-DEOXY MONOSACCHARIDES FROM H-1-NMR RELAXATION MEASUREMENTS IN SOLUTION

Determination of selective and biselective H-1 spin-lattice relaxation rates combined with steady-state and transient H-1-H-1 NOE data allow ed calculation of intramolecular proton-proton distances in 2-acetamid o-2-deoxy-D-glucosides (1a and 1b), 2-acetamido-2-deoXy-D-mannoses (5a and 5b) and their acetylated derivatives. These measurements were sup plemented by DESERT studies using derivatives selectively labeled by H -2 at position 2. These distance data are in good correlation with lit erature values obtained by X-ray crystallography. Interproton distance measurements allow the determination of relative configurations, incl uding that of the anomeric carbon, in hexopyranose rings in cases wher e other methods, like those based on scalar coupling constants, fail.