{"doi":"10.1139/v82-045","title":"Synthesis of the colitose determinant of <i>Escherichia</i><i>coli</i> O111 and 3,6-di-<i>O</i>-(α-<scp>D</scp>-galactopyranosyl)-α-<scp>D</scp>-glucopyranoside","abstract":"<jats:p> The syntheses of two branched trisaccharides, which constitute important elements of enterobacterial lipopolysaccharides are described. The common structural feature of each trisaccharide is α-D-glucopyranoside, upon which branching occurs at the O-3 and O-6 positions. Selective blocking of this hexoside at O-2 and O-4 by persistent blocking groups was accomplished by benzylation of 1,6-anhydro-β-D-glucopyranoside (1). Acetolysis of the product 2 afforded a mixture of anomeric triacetates 3 from which the corresponding 3,6-di-O-acetyl-2,4-O-benzyl-α-D-glucopyranosyl chloride (4) was prepared. The α and β 8-methoxycarbonyloctyl glycosides 5 and 6 were obtained in the ratio ~2:1, when 4 was reacted with 8-methoxycarbonyloctanol. Transesterification of the α-glycoside 5 gave the aglyconic intermediate 7 from which each trisaccharide could be obtained in a one step reaction. Thus glycosylation of 7 with tetra-O-benzyl-α-D-galactopyranosyl chloride (8) or 2,4-di-O-benzyl-3,6-dideoxy-α-L-xylo-hexopyranosyl chloride (10) gave the trisaccharides 11 and 13. In both cases removal of blocking groups was achieved in a single hydrogenolysis step. Trisaccharide 12 represents a trisaccharide sequence present in the core saccharide of Salmonella lipopolysaccharides, while the colitose containing trisaccharide 14 is an essential element of the E. coli O111 O-antigen. </jats:p>","journal":"Canadian Journal of Chemistry","year":1982,"id":601370,"datarank":0.5416376868966337,"base_score":3.6109179126442243,"endowment":3.6109179126442243,"self_citation_contribution":0.5416376868966337,"citation_network_contribution":0.0,"self_endowment_contribution":0.5416376868966337,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":36,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1192405,"name":"David R. 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Acetolysis of the product 2 afforded a mixture of anomeric triacetates 3 from which the corresponding 3,6-di-O-acetyl-2,4-O-benzyl-α-D-glucopyranosyl chloride (4) was prepared. The α and β 8-methoxycarbonyloctyl glycosides 5 and 6 were obtained in the ratio ~2:1, when 4 was reacted with 8-methoxycarbonyloctanol. Transesterification of the α-glycoside 5 gave the aglyconic intermediate 7 from which each trisaccharide could be obtained in a one step reaction. Thus glycosylation of 7 with tetra-O-benzyl-α-D-galactopyranosyl chloride (8) or 2,4-di-O-benzyl-3,6-dideoxy-α-L-xylo-hexopyranosyl chloride (10) gave the trisaccharides 11 and 13. In both cases removal of blocking groups was achieved in a single hydrogenolysis step. Trisaccharide 12 represents a trisaccharide sequence present in the core saccharide of Salmonella lipopolysaccharides, while the colitose containing trisaccharide 14 is an essential element of the E. coli O111 O-antigen. </jats:p>","is_dataset_classified":null,"base_score":3.6109179126442243,"endowment":3.6109179126442243,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"21097893","pmcid":null,"openalex_id":"https://openalex.org/W1999351994","authors":[],"funders":[],"total_grants":0,"fwci":3.3848,"citation_percentile":0.91049252,"influential_citations":0,"citation_trend":[{"year":2013,"count":1},{"year":2015,"count":2},{"year":2017,"count":1},{"year":2018,"count":2},{"year":2023,"count":2},{"year":2024,"count":1}],"oa_status":"closed","license":"http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining","oa_locations":[{"url":"https://cdnsciencepub.com/doi/pdf/10.1139/v82-045","host_type":"publisher"},{"url":"https://doi.org/10.1139/v82-045","host_type":"journal"}],"fields_of_study":["Carbohydrate Chemistry and Synthesis","Escherichia coli research studies","Probiotics and Fermented Foods"],"mesh_terms":[],"keywords":["Trisaccharide","Chemistry","Hydrogenolysis","Glycoside","Glycosylation","Stereochemistry","Anomer","Chloride","Organic chemistry","Catalysis","Biochemistry"],"sdg_mappings":[],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-07-29T16:06:27.453478Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}