Synthesis of 6-deoxyheptose derivatives via cyclic sulfates and oxetanes

Two approaches for the chain elongation and synthesis of 6-deoxyheptose der ivatives are described. The first one is based on the regioselective ring o pening of 4,6-cyclic sulfate glycopyranoside derivatives at carbon 6 by cya nide ion. The second approach involves the ring expansion of 5,6-anhydro to 5,7-anhydro sugars and subsequent opening of the resulting oxetane derivat ive using acetate ion as nucleophile.