{"id":{"repo_id":"mit","oai_identifier":"oai:dspace.mit.edu:1721.1/57703"},"canonical_url":"https://search.dev.ndltd.org/etd/mit/oai:dspace.mit.edu:1721.1/57703","repository":{"repo_id":"mit","name":"MIT","base_url":"https://dspace.mit.edu/oai/request"},"display":{"title":"Directing group-free endo-selective epoxide-opening cascades","abstract":"[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily complex molecules. In practice, however, such cascades are strongly disfavored, and non-natural directing groups must be covalently attached to each epoxide to overcome this inherent bias. We report herein a general method for directing group-free cascades that also supports the postulated biosynthesis. The two salient aspects of this strategy are a single design principle (a template) and a promoter that both donates and accepts hydrogen bonds. Water is the superior promoter, and it is most effective at approximately pH 7.","abstract_html":"[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily complex molecules. In practice, however, such cascades are strongly disfavored, and non-natural directing groups must be covalently attached to each epoxide to overcome this inherent bias. We report herein a general method for directing group-free cascades that also supports the postulated biosynthesis. The two salient aspects of this strategy are a single design principle (a template) and a promoter that both donates and accepts hydrogen bonds. Water is the superior promoter, and it is most effective at approximately pH 7.","abstract_has_math":false,"creators":["Vilotijević, Ivan"],"institution":"Massachusetts Institute of Technology","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":"Massachusetts Institute of Technology. Dept. of Chemistry.","school":null,"contributors":[],"advisors":["Timothy F. Jamison."],"committee_chairs":[],"committee_members":[],"year":2010,"date_issued":"2010","date_published":"2010","updated_at":"2026-07-22T22:22:11Z","subjects":["Chemistry."],"languages":["eng"],"rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"rights_urls":["http://dspace.mit.edu/handle/1721.1/7582"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/1721.1/57703","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Timothy F. Jamison."]},{"key":"dc:contributor.department","label":"Department","values":["Massachusetts Institute of Technology. Dept. of Chemistry."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["Massachusetts Institute of Technology. Dept. of Chemistry."]},{"key":"dc:creator","label":"Author","values":["Vilotijević, Ivan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2010-08-30T14:46:11Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2010-08-30T14:46:11Z"]},{"key":"dc:date.issued","label":"Date","values":["2010"]},{"key":"dc:publisher","label":"Institution","values":["Massachusetts Institute of Technology"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry."]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://dspace.mit.edu/handle/1721.1/7582"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/1721.1/57703"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2010.","Vita. Cataloged from PDF version of thesis.","Includes bibliographical references (p. 108-112)."]},{"key":"dc:description.abstract","label":"Abstract","values":["[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily complex molecules. In practice, however, such cascades are strongly disfavored, and non-natural directing groups must be covalently attached to each epoxide to overcome this inherent bias. We report herein a general method for directing group-free cascades that also supports the postulated biosynthesis. The two salient aspects of this strategy are a single design principle (a template) and a promoter that both donates and accepts hydrogen bonds. Water is the superior promoter, and it is most effective at approximately pH 7."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph.D."]},{"key":"dc:title","label":"Title","values":["Directing group-free endo-selective epoxide-opening cascades"]}]}],"canonical_facts":{"dc:contributor.advisor":["Timothy F. Jamison."],"dc:contributor.department":["Massachusetts Institute of Technology. Dept. of Chemistry."],"dc:contributor.other":["Massachusetts Institute of Technology. Dept. of Chemistry."],"dc:creator":["Vilotijević, Ivan"],"dc:date.accessioned":["2010-08-30T14:46:11Z"],"dc:date.available":["2010-08-30T14:46:11Z"],"dc:date.issued":["2010"],"dc:description":["Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2010.","Vita. Cataloged from PDF version of thesis.","Includes bibliographical references (p. 108-112)."],"dc:description.abstract":["[image] The proposed biogenesis of the ladder polyethers features a dramatic series of epoxide opening reactions, elegantly accounts for the structural and stereochemical features of all related natural products, and, in principle, could significantly simplify the synthesis of these extraordinarily complex molecules. In practice, however, such cascades are strongly disfavored, and non-natural directing groups must be covalently attached to each epoxide to overcome this inherent bias. We report herein a general method for directing group-free cascades that also supports the postulated biosynthesis. The two salient aspects of this strategy are a single design principle (a template) and a promoter that both donates and accepts hydrogen bonds. Water is the superior promoter, and it is most effective at approximately pH 7."],"dc:description.degree":["Ph.D."],"dc:identifier.uri":["http://hdl.handle.net/1721.1/57703"],"dc:language.iso":["eng"],"dc:publisher":["Massachusetts Institute of Technology"],"dc:rights":["M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission."],"dc:rights.uri":["http://dspace.mit.edu/handle/1721.1/7582"],"dc:subject":["Chemistry."],"dc:title":["Directing group-free endo-selective epoxide-opening cascades"],"dc:type":["Thesis"]},"updated_at":"2026-07-22T22:22:11Z"}