Four galactofuranose-containing disaccharides have been prepared utilising various thioimidates [Galf-SC(=NR)XR'] and suitably protected acceptors as key precursors. We observed that the efficiency of the coupling reactions was particularly dependent on the aglycon present on the furanosyl donor when copper(II) ions were used as the promoter, and that activation could be correlated with the nature of the third heteroatorn, X. (c) 2006 Elsevier Ltd. All rights reserved.
A novel synthesis of d-galactofuranosyl, d-glucofuranosyl and d-mannofuranosyl 1-phosphates based on remote activation of new and free hexofuranosyl donors
The selective synthesis of 1,2-cis-hexofuranosyl 1-phosphates was readily accomplished according to a procedure based on the 'Remote Activation Concept'. This approach required (i) the preparation of suitable 1,2-trans-hexofuranosyl donors, so that new heterocyclic thiofuranosides were designed and synthesized, (ii) the stereocontrolled phosphorylation of the corresponding unprotected donors and (iii) the simple and fast purification of the resulting anomeric phosphates. This approach showed to be equally efficient in the galactose, glucose and mannose series. (C) 2002 Elsevier Science Ltd. All rights reserved.