Synthesis of sialic acid-containing nucleotide sugars: CMP-sialic acid analogs.

Syntheses of some sialic acid-containing nucleotide sugars are reported. The reaction of methyl[(2-hydroxy)ethyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-D-glycero-alpha-D-galacto -2- nonulopyranosid]onate (4) with various fully protected hydrogen phosphonates of nucleotides (5a-c) in the presence of 2,4,6-triisopropylbenzenesulfonyl chloride (TPS-Cl), gave, after oxidation and deprotection, the corresponding sialic acid-containing nucleotide sugar analogs (8a-c).