Mimics of the structural elements of type III group B Streptococcus capsular polysaccharide. Part III: two repeating units (octasaccharide) with (S)-1-carboxyethyl groups replacing sialic acids

A chemical synthesis of octasaccharide 1 is described in which (S)-1-carboxyethyl groups replace sialic acid residues to yield a mimic of two repeating units of the type III group B Streptococcus capsular polysaccharide.