biostudies-literatureSi ACouncil of Scientific and Industrial Research (CSIR), New Delhi, India47-50https://www.ebi.ac.uk/biostudies/studies/S-EPMC4906483biostudies-literatureUnknown5(1)A convergent [3+2] block synthetic strategy was developed for the synthesis of the pentasaccharide repeating unit of the cell wall O-antigen of Escherichia coli O11 strain in excellent yield in a minimum number of steps. Several suitably functionalized thioglycoside derivatives were used as glycosyl donors during the synthesis of the target compound. A thioglycoside was the glycosyl donor used to couple with another thioglycoside derivative in a highly stereoselective manner exploiting the difference of their reactivity profile. A combination of Niodosuccinimide (NIS) and perchloric acid supported over silica gel (HClO4-SiO2) was used as a thiophilic glycosylation activator system in all stereoselective glycosylation reactions. HClO4-SiO2 acted as a user-friendly solid acid catalyst. Yields were very good in all glycosylation steps with a high stereoselective outcome. The synthetic pentasaccharide could be coupled to an appropriate protein to furnish a glycoconjugate derivative for its use in immunochemical studies.ChemistryOpenExpedient Synthesis of the Pentasaccharide Repeating Unit of the Polysaccharide O-Antigen of Escherichia coli O11.PMC490648302(0038)/11/EMR-IISi AMisra AKfalseExpedient Synthesis of the Pentasaccharide Repeating Unit of the Polysaccharide O-Antigen of Escherichia coli O11.A convergent [3+2] block synthetic strategy was developed for the synthesis of the pentasaccharide repeating unit of the cell wall O-antigen of Escherichia coli O11 strain in excellent yield in a minimum number of steps. Several suitably functionalized thioglycoside derivatives were used as glycosyl donors during the synthesis of the target compound. A thioglycoside was the glycosyl donor used to couple with another thioglycoside derivative in a highly stereoselective manner exploiting the difference of their reactivity profile. A combination of Niodosuccinimide (NIS) and perchloric acid supported over silica gel (HClO4-SiO2) was used as a thiophilic glycosylation activator system in all stereoselective glycosylation reactions. HClO4-SiO2 acted as a user-friendly solid acid catalyst. Yields were very good in all glycosylation steps with a high stereoselective outcome. The synthetic pentasaccharide could be coupled to an appropriate protein to furnish a glycoconjugate derivative for its use in immunochemical studies.2016-01-01T00:00:00Z2016 Feb2025-04-19T23:19:26.066Z2019-03-27T02:15:58ZS-EPMC49064832730821110.1002/open.201500129