A new aspect of the reactivity of sodium dithionite provides a facile route to 2-deoxy-α-glycosides

Sodium dithionite, which is known to cause dehalogenation of α-halo carbonyl compounds, also induces dehalogenation of protected 2-iodo-2-deoxyglycosides. Combined with the well-known iodonium-mediated haloalkoxylation, this reaction provides an easy, mild and highly stereoselective route for preparation of 2-deoxy-α-glycosides from glycals.