Convenient synthesis of mono and cyclic sulphates of carbohydrates via triflate displacement

Abstract
The 2,3-anhydropyranoside-4-triflates (1), (3), and (6) react with tetrabutylammonium hydrogen sulphate to afford the sulphate esters (2), (4), and (7) respectively. In the case of triflates (3) and (6) the cyclic sulphates (5) and (8) were obtained as major products. The benzyl pyranoside (8) was successfully deblocked to yield the free sugar cyclic sulphate (9). The 1H NMR spectra of the newly synthesized sulphates have been discussed in detail. The 13C NMR spectral data are also described.