Synthesis and conformational analysis of glycomimetic analogs of thiochitobiose

The synthesis of six analogs of N,N'-diacetylchitobiose is reported, including a novel transglycosylation reaction for the preparation of S-aryl thioglycosides. The conformations of the compounds were studied by a combination of NMR spectroscopy and molecular modeling, using force field calculations. In the case of the S-aryl thioglycosides with exclusively S-glycosidic linkages, dihedral angles of the disaccharidic S-glycosidic bonds, Phi' and Psi' and of the S-arylglycoside bonds, Phi and Psi, were found to be similar, whereas they were different in mixed glycosides and in a thiazoline derivative. An adequate correlation between the calculated H,H-distances of the local minima and the measured NOE contacts was achieved by applying population-weighted averages over participating conformers based on weighted relative energies. (C) 2009 Elsevier Ltd. All rights reserved.