Enantioselective synthesis of N-Cbz-protected 6-amino-6-deoxymannose, -talose, and -gulose

The enantioselective synthesis of three 6-amino-6-deoxy sugars has been achieved in six to eight steps from furfural. A sequence of diastereoselective oxidation and reduction reactions produced Cbz-protected 6-aminomannose from furfuryl alcohol 3. The incorporation of a Mitsunobu reaction into the reaction sequence allows for the selective synthesis of both N-Cbz-protected 6-aminotalose and 6-aminogulose. The overall procedure allows for the synthesis of either enantiomer of these three aminosugars. [reaction: see text]