Scheme 5: Synthesis of hexasaccharide 3 via a one-pot (1 + 2 + 2 + 1) approach.

Two hexasaccharides 3 (terminal unit) and 3′ (elongation repeating unit) were efficiently assembled through one-pot method.

Two hexasaccharides 3 (terminal unit) and 3′ (elongation repeating unit) were efficiently assembled through one-pot method.