{"doi":"10.1002/ejoc.202200320","title":"Influence of 3‐Thio Substituents on Benzylidene‐Directed Mannosylation. Isolation of a Bridged Pyridinium Ion and Effects of 3‐<i>O</i>‐Picolyl and 3‐<i>S</i>‐Picolyl Esters","abstract":"Abstract The influence on glycosyl selectivity of substituting oxygen for sulfur at the 3‐position of 4,6‐ O ‐benzylidene‐protected mannopyranosyl thioglycosides is reported and varies considerably according to the protecting group employed at the 3‐position. The substitution of a thioether at the 3‐position for the more usual 3‐ O ‐benzyl ether results in a significant loss of selectivity. The installation of a 3‐ S ‐picolinyl thioether results in a complex reaction mixture, from which a stable seven‐membered bridged bicyclic pyridinium ion is isolated, while the corresponding 3‐ O ‐picolinyl ether affords a highly α‐selective coupling reaction. A 3‐ O ‐picolyl ester provides excellent β‐selectivity, while the analogous 3‐ S ‐picolyl thioester gives a highly α‐selective reaction. The best β‐selectivity is seen with a 3‐deoxy‐3‐(2‐pyridinyldisulfanyl) system. These observations are discussed in terms of the influence of the various substituents on the central glycosyl triflate – ion pair equilibrium.","journal":"European Journal of Organic Chemistry","year":2022,"id":277666,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":7,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9544,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":262345,"name":"David Crich","orcid":"0000-0003-2400-0083","position":1,"is_corresponding":false},{"id":949284,"name":"Timothy F. McMillan","orcid":"0000-0002-0622-4051","position":0,"is_corresponding":true}],"reference_count":61,"raw_metadata":null,"created_at":"2026-07-19T00:28:39.226969Z","pmid":"36340645","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":[]}