Iodomethyl group as a hydroxymethyl synthetic equivalent:: Application to the syntheses of D-manno-hept-2-ulose and L-fructose derivatives

The one-carbon elongation of aldoses to ketoses using iodomethyllithium as the key reagent in the homologation step is exemplified by the preparation of two carbohydrates of chemical and biological interests: (D)-manno-hept-2-ulose from (D)-mannose and (L)-fructose from (L)-arabinose.