{"id":{"repo_id":"utswmed","oai_identifier":"oai:utswmed-ir.tdl.org:2152.5/1261"},"canonical_url":"https://search.dev.ndltd.org/etd/utswmed/oai:utswmed-ir.tdl.org:2152.5/1261","repository":{"repo_id":"utswmed","name":"University of Texas Southwestern Medical Center","base_url":"https://utswmed-ir.tdl.org/server/oai/request"},"display":{"title":"Synthesis of Dimeric Pyrrole-Imidazole Alkaloids","abstract":"Dimeric pyrrole-imidazole alkaloids, also known as oroidin family of alkaloids, are a class of marine natural products with unique structural diversity and complexity. Focusing on the synthesis of the higher order dimeric pyrrole-imidazole alkaloids, my graduate work comprises two components: a synthetic study of massadine and the total synthesis of ageliferin, as describe herein. These highly nitrogenated marine natural products possess a densely functionalized [3+2] or [4+2] dimerization core skeleton, which present significant synthetic challenges. A manganese(III)-mediated oxidative radical cyclization has been developed to construct the core skeleton of these pyrrole-imidazole dimers and its mechanism is investigated by the methods of computational chemistry. Ent-15-epi-5,11-dioxomassadine has been synthesized by using a biomimetic oxidative ring contraction converting ageliferin skeleton to massadine skeleton with stereochemical control, followed by an oxidative cyclization to construct the oxo-bridge. An asymmetric total synthesis of ageliferin is described, featuring an early installation of 2-azidoimidazole for the oxidative radical cyclization and a phosphorus imide group as a novel protecting group for 2-aminoimidazole. These synthetic studies support the possibility that a single-electron transfer (SET) reaction and a pinacol-type rearrangement may be used in nature as a way to produce ageliferin and massadine.","abstract_html":"Dimeric pyrrole-imidazole alkaloids, also known as oroidin family of alkaloids, are a class of marine natural products with unique structural diversity and complexity. Focusing on the synthesis of the higher order dimeric pyrrole-imidazole alkaloids, my graduate work comprises two components: a synthetic study of massadine and the total synthesis of ageliferin, as describe herein. These highly nitrogenated marine natural products possess a densely functionalized [3+2] or [4+2] dimerization core skeleton, which present significant synthetic challenges. A manganese(III)-mediated oxidative radical cyclization has been developed to construct the core skeleton of these pyrrole-imidazole dimers and its mechanism is investigated by the methods of computational chemistry. Ent-15-epi-5,11-dioxomassadine has been synthesized by using a biomimetic oxidative ring contraction converting ageliferin skeleton to massadine skeleton with stereochemical control, followed by an oxidative cyclization to construct the oxo-bridge. An asymmetric total synthesis of ageliferin is described, featuring an early installation of 2-azidoimidazole for the oxidative radical cyclization and a phosphorus imide group as a novel protecting group for 2-aminoimidazole. These synthetic studies support the possibility that a single-electron transfer (SET) reaction and a pinacol-type rearrangement may be used in nature as a way to produce ageliferin and massadine.","abstract_has_math":false,"creators":["Wang, Xiao"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Chen, Chuo"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-01-17T16:18:31Z","date_published":"2013-01-17T16:18:31Z","updated_at":"2026-07-24T05:52:17Z","subjects":["Imidazoles","Pyrroles"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["841579494"],"render_values":[{"text":"841579494","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/2152.5/1261","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Chen, Chuo"]},{"key":"dc:creator","label":"Author","values":["Wang, Xiao"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-01-17T16:18:31Z","2013-01-17"]},{"key":"dc:type","label":"Dc Type","values":["Thesis","Text"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Imidazoles","Pyrroles"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://hdl.handle.net/2152.5/1261","841579494"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Dimeric pyrrole-imidazole alkaloids, also known as oroidin family of alkaloids, are a class of marine natural products with unique structural diversity and complexity. Focusing on the synthesis of the higher order dimeric pyrrole-imidazole alkaloids, my graduate work comprises two components: a synthetic study of massadine and the total synthesis of ageliferin, as describe herein. These highly nitrogenated marine natural products possess a densely functionalized [3+2] or [4+2] dimerization core skeleton, which present significant synthetic challenges. A manganese(III)-mediated oxidative radical cyclization has been developed to construct the core skeleton of these pyrrole-imidazole dimers and its mechanism is investigated by the methods of computational chemistry. Ent-15-epi-5,11-dioxomassadine has been synthesized by using a biomimetic oxidative ring contraction converting ageliferin skeleton to massadine skeleton with stereochemical control, followed by an oxidative cyclization to construct the oxo-bridge. An asymmetric total synthesis of ageliferin is described, featuring an early installation of 2-azidoimidazole for the oxidative radical cyclization and a phosphorus imide group as a novel protecting group for 2-aminoimidazole. These synthetic studies support the possibility that a single-electron transfer (SET) reaction and a pinacol-type rearrangement may be used in nature as a way to produce ageliferin and massadine."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Synthesis of Dimeric Pyrrole-Imidazole Alkaloids"]}]}],"canonical_facts":{"dc:contributor":["Chen, Chuo"],"dc:creator":["Wang, Xiao"],"dc:date":["2013-01-17T16:18:31Z","2013-01-17"],"dc:description":["Dimeric pyrrole-imidazole alkaloids, also known as oroidin family of alkaloids, are a class of marine natural products with unique structural diversity and complexity. Focusing on the synthesis of the higher order dimeric pyrrole-imidazole alkaloids, my graduate work comprises two components: a synthetic study of massadine and the total synthesis of ageliferin, as describe herein. These highly nitrogenated marine natural products possess a densely functionalized [3+2] or [4+2] dimerization core skeleton, which present significant synthetic challenges. A manganese(III)-mediated oxidative radical cyclization has been developed to construct the core skeleton of these pyrrole-imidazole dimers and its mechanism is investigated by the methods of computational chemistry. Ent-15-epi-5,11-dioxomassadine has been synthesized by using a biomimetic oxidative ring contraction converting ageliferin skeleton to massadine skeleton with stereochemical control, followed by an oxidative cyclization to construct the oxo-bridge. An asymmetric total synthesis of ageliferin is described, featuring an early installation of 2-azidoimidazole for the oxidative radical cyclization and a phosphorus imide group as a novel protecting group for 2-aminoimidazole. These synthetic studies support the possibility that a single-electron transfer (SET) reaction and a pinacol-type rearrangement may be used in nature as a way to produce ageliferin and massadine."],"dc:format":["application/pdf"],"dc:identifier":["https://hdl.handle.net/2152.5/1261","841579494"],"dc:subject":["Imidazoles","Pyrroles"],"dc:title":["Synthesis of Dimeric Pyrrole-Imidazole Alkaloids"],"dc:type":["Thesis","Text"]},"updated_at":"2026-07-24T05:52:17Z"}