Studies on Sialic Acids. XXX. Synthesis of 2, 7-Anhydrosialic Acid

Abstract

N-Acetyl-and N-glycolyl-2, 7-anhydroneuraminic acid were synthesized from methyl 5-acetamido-3, 5-dideoxy-2-thio-α-D-glycero-D-galacto-2-nonulopyranosonate in high yield. The structures and stereochemistry of these glycosanic sialic acids were elucidated from ¹H-NMR spectra and X-ray crystal analysis. The ring systems of N-acetyl- and N-glycolyl-2, 7-anhydroneuraminic acid (1 and 10) were determined to have the same ²C₅(D) conformation.