Synthesis of the Pentasaccharide Repeating unit Corresponding to the Cell-wall O-antigenic Polysaccharide of Oral Bacteria Porphyromonas circumdentaria NCTC 12469

Abstract A concise chemical synthetic strategy has been developed for the synthesis of the pentasaccharide repeating unit of the cell-wall O-antigen of Porphyromonas circumdentaria NCTC 12469, which plays an important role in the development of periodontal disease. Several regio- and stereoselective glycosylations were carried out with high yields and satisfactory stereochemistry at the glycosidic linkages using suitably functionalized thioglycoside intermediates as glycosyl donors.