The 5, 6-O-thiocarbonyl-α-D-glucofuranose derivatives 2, when subjected to one of the following reactions, undergo a radical-promoted thione-thiol rearrangement to yield the 5-S-thiolcarbonates of gluco-configuration 8 as the major product. The reactions are, (A) thermolysis with a catalytic amount of tributyltin hydride and AIBN, (B) photolysis with hexabutyldistannane, and (C) thermolysis with dimethyl phosphonate and benzoyl peroxide. On the other, hand, theromolysis of 2 with trialkylsilane (condition D) yielded olefins 13 as the major product. The 5-S-gluco product 8 was converted, in three steps, to 5-thioglucose (21) in 55% yield.