Chemical modification of trehalose. Part XIII. Synthesis of some 4,4′-difluoro- and 4,4′,6,6′-tetrafluoro-analogues

Abstract

Suitably protected 4,4′-disulphonates and 4,4′,6,6′-tetrasulphonates of trehalose and galacto-trehalose have been subjected to fluoride displacement reactions with tetra-n-butylammonium fluoride in acetonitrile. In the cases of the trehalose sulphonates the reactions proceeded with configurational inversion at C-4 to give the appropriate di- and tetra-fluoro-galacto-trehalose derivatives in moderate yields from which the protecting groups were subsequently removed. On the other hand, the galacto-trehalose sulphonates underwent extensive elimination and in consequence the required di- and tetra-fluorotrehaloses were only obtained in poor yields.