Facile Synthesis of 4-Acylamino-2,6-anhydro-2,3,4-trideoxy-D-glycero-D-galacto-non-2-enoic Acids

The title compounds were synthesized from 3-deoxy-D-glycero-D-galacto-2-nonulosonic acid (5, KDN) by a new method which is similar to the Ritter reaction. The structures on these compounds were elucidated from the MS, elemental analysis, 1H-NMR and 13C-NMR, data, and the stereochemistry of methyl 4-benzoylamino-5, 7, 8, 9-tetra-O-acetyl-2, 6-anhydro-2, 3-dideoxy-D-glycero-D-galacto-non-2-enonate (13) was determined by X-ray crystallographic analysis.