Synthesis of 2,3,4-Trideoxy-2,3,4-trifluoroglucose

There
is an increasing interest in investigating how polyfluorination
of carbohydrates modifies their physical and biological properties.
An example that has caught much attention is 2,3,4-trideoxy-2,3,4-trifluoroglucose.
Four syntheses of this compound have been reported, which are either
low yielding or long (13 or more steps). We report a 6-step synthesis
of 2,3,4-trideoxy-2,3,4-trifluoroglucose starting from levoglucosan.
The solution-phase structure of an intermediate, 1,6-anhydro-2,4-dideoxy-2,4-difluoroallose,
features a rare example of a bifurcated F···H­(O)···F
hydrogen bond and is compared to its crystal structure.