Synthesis of Branched 4-Thiofuranoses

In the branched-chain series, the 4-thioapiofuranoside 78 was the first reported example prepared from the apiose derivative 76 via acid-catalyzed methanolysis of thiol 77, with migration of the acetal group. 

Samuelsson et al. have prepared 4-thiofuranosides 83 via regioselective opening of an episulflde with allylmagnesium bromide. This furnished thiol 79 

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