Enantioselective synthesis of 2-deoxy- and 2,3-dideoxyhexoses.

[reaction: see text] The enantioselective syntheses of C-6 O-TBS- and N-Cbz-protected 2-deoxy- and 2,3-dideoxysugars have been achieved in 6-8 steps from furfural. A combination of chemo-, regio-, and diastereoselective oxidation and reduction reactions produced deoxysugars with various C-6 substitution. A key development of this route was the use of o-nitrobenzenesulfonylhydrazide (NBSH) as a diimide precursor. These overall procedures allow for the synthesis of eight deoxysugars in either enantiomeric form.