Synthesis of furanose glycals from furanose 1,2-diols and their cyclic thiocarbonate esters

Two new methods for the synthesis of furanoid glycals are described. Both procedures were shown to be faster and cheaper that those previously reported. Protected 1,2-dihydroxypento- and hexo-furanose derivatives with the d-xylo, d-gluco and d-ribo, d-allo configurations were used as starting material to afford the corresponding C-3,4 d-threo and d-erythro glycals derivatives.