Synthesis of Kojidextrins and Their Protein Conjugates. Incidence of Steric Mismatch in Oligosaccharide Synthesis.

Kojidextrins are biologically important oligosaccharides that are involved in many physiological processes including protein glycosylation and bacterial growth. As part of our project to explore the role kojidextrins may play in bacterial pathogenesis, here we report synthetic routes to kojibiose (54), -triose (58), -tetraose (64), and -pentaose (69) equipped with alpha-linked (hydrazinocarbonyl)pentyl aglycon, using linear and convergent strategies. In the search for a rapid convergent strategy for the construction of extended kojidextrins, four kojibiose donors (1-4) were synthesized that contain acyl- and ether-type protecting groups in various ratios.