Reaction Products from Fischer's Methylation of 3-Deoxy-D-glycero-D-galacto-2-nonulosonic Acid (KDN)

Several compounds were isolated from the Fischer's methylation reaction mixture of 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (KDN) with hydrochloric acid or methanesulfonic acid in methanol. The major product was methyl (methyl 3-deoxy-β-D-glycero-D-galacto-2-nonulopyranosid)onate (2), which we have already reported. New furan derivatives and a 4, 8-anhydro product were also isolated. The structures of these compounds were elucidated by nuclear magnetic resonance spectroscopy and X-ray crystallographic analysis.