Koenigs-Knorr Glycosylation with Neuraminic Acid Derivatives

Scheme 1

(a) MeOH/HCl; (b) Ac₂O/Py; (c) AcCl, MeOH/CHCl₃; (d) Ag₂CO₃ (Ag₂CO₃/AgOTf), CH₂Cl₂, MS 4Å; (e) MeONa/MeOH; (f) NaOH/H₂O; (g) H₂, Pd/C.