Figure 2

Synthesis of sulfo-sialic acid analogues. α-Anomers 2a, 3a, 5a and 7a are in the R anomeric configuration with equatorial anomeric functional groups, and β-anomers 2b, 3b, 4b, 5b, 6b, 7b and 8b are in the S anomeric configuration with axial anomeric functional groups.