Studies on sialic acids. XVIII: Synthesis of aryl-α-glycosides of 3-deoxy-D-glycero-D-galacto-2-nonulopyranosonic acid (KDN)

Abstract

Condensation of sodium phenoxide, sodium p-nitrophenoxide, and sodium 4-methylumbelliferonate with benzyl (4, 5, 7, 8, 9-penta-O-acetyl-3-deoxy-D-glycero-β-D-galacto-2-nonulopyranosyl chlorid)onate under the Williamson reaction conditions gave the corresponding α-glycosides in good yields. Deprotection reaction of these α-glycosides gave sodium salts of phenyl-, p-nitrophenyl-, and 4-methylumbelliferonyl-α-glycosides of 3-deoxy-D-glycero-D-galacto-2-nonulopyranosonic acid (KDN). The structure and stereochemistry of the glycosylation products were determined by proton nuclear magnetic resonance (1H-NMR) and circular dichroism (CD) spectral analysis.