Campylobacter jejuni is a Gram-negative bacterium and is the main cause of illnesses related to gastroenteritis in humans. As the outermost structure of Campylobacter jejuni, CPS were made into glycoconjugate vaccines to fight Campylobacter jejuni infection and and have shown promising results.
Structural analysis of CPS related to C. jejuni serotype HS:4 revealed a repeating unit consisting of 4-substituted N-acetyl-β-D-glucopyranosamine and 3-substituted 6-deoxy-β-D-ido-heptopyranose. To this end, the focus of the thesis are synthetic studies on 6-deoxy-β-D-ido-heptopyranosides which could be attached to a carrier protein such as CRM197 for immunological studies. Two 6-deoxy-β-D-ido-heptopyranosides (115 and 116) have been successfully prepared for the first time.
An efficient protocol to regioselectively convert one O-isopropylidene into di-O-acetates via acetolysis has been established for di-O-isopropylidene-protected D-galacto- and D-fructo-pyranosyl systems (Chapter 3). Trifluoroacetic acid (TFA) was found to achieve the regioselective acetolysis of a series of di-O-isopropylidene-protected hexopyranosides in acetic anhydride.