{"id":{"repo_id":"uwo","oai_identifier":"oai:uwo.scholaris.ca:20.500.14721/33725"},"canonical_url":"https://search.dev.ndltd.org/etd/uwo/oai:uwo.scholaris.ca:20.500.14721/33725","repository":{"repo_id":"uwo","name":"Western University","base_url":"https://uwo.scholaris.ca/server/oai/request"},"display":{"title":"Total Synthesis of (+)-nemorensic acid: En Route to (-)-callosine","abstract":"An intramolecular oxime ether cyclopropane annulation developed in 2008 by Kerr has been shown to form 2,5-trans and 2,5-cis pyrrolidines in a stereodivergent fashion. When the oxime ether is functionalized with an enantioenhanced α-hydroxy substitutent and a leaving group, the pyrrolizidine core of (-)-callosine can be accessed in short order. Callosine is a structurally unique pyrrolizidine alkaloid isolated from Mexican flowering plant Senecio callosus. In an effort to complete the total synthesis, the total synthesis of (+)-nemorensic acid, the necic acid component of the callosine, has been established. Attempts at appending the ansa bridge via esterification and macrolactonization are discussed.","abstract_html":"An intramolecular oxime ether cyclopropane annulation developed in 2008 by Kerr has been shown to form 2,5-trans and 2,5-cis pyrrolidines in a stereodivergent fashion. When the oxime ether is functionalized with an enantioenhanced α-hydroxy substitutent and a leaving group, the pyrrolizidine core of (-)-callosine can be accessed in short order. Callosine is a structurally unique pyrrolizidine alkaloid isolated from Mexican flowering plant Senecio callosus. In an effort to complete the total synthesis, the total synthesis of (+)-nemorensic acid, the necic acid component of the callosine, has been established. Attempts at appending the ansa bridge via esterification and macrolactonization are discussed.","abstract_has_math":false,"creators":["Vriesen, Matthew R"],"institution":"The University of Western Ontario","degree_name":"M Sc","degree_level":null,"degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":[],"advisors":["Michael Kerr"],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-04-20","date_published":"2016-04-20","updated_at":"2026-07-27T21:55:54Z","subjects":["nemorensic acid","callosine","total synthesis","cyclopropane","annulation"],"languages":["en_ca"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://hdl.handle.net/20.500.14721/33725","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Michael Kerr"]},{"key":"dc:creator","label":"Author","values":["Vriesen, Matthew R"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-07-10T19:55:01Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-07-10T19:55:01Z"]},{"key":"dc:date.issued","label":"Date","values":["2016-04-20"]},{"key":"dc:publisher","label":"Institution","values":["The University of Western Ontario"]},{"key":"dc:type","label":"Dc Type","values":["thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M Sc"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["nemorensic acid","callosine","total synthesis","cyclopropane","annulation"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_ca"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/20.500.14721/33725"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."]},{"key":"dc:description.abstract","label":"Abstract","values":["An intramolecular oxime ether cyclopropane annulation developed in 2008 by Kerr has been shown to form 2,5-trans and 2,5-cis pyrrolidines in a stereodivergent fashion. When the oxime ether is functionalized with an enantioenhanced α-hydroxy substitutent and a leaving group, the pyrrolizidine core of (-)-callosine can be accessed in short order. Callosine is a structurally unique pyrrolizidine alkaloid isolated from Mexican flowering plant Senecio callosus. In an effort to complete the total synthesis, the total synthesis of (+)-nemorensic acid, the necic acid component of the callosine, has been established. Attempts at appending the ansa bridge via esterification and macrolactonization are discussed."]},{"key":"dc:title","label":"Title","values":["Total Synthesis of (+)-nemorensic acid: En Route to (-)-callosine"]}]}],"canonical_facts":{"dc:contributor.advisor":["Michael Kerr"],"dc:creator":["Vriesen, Matthew R"],"dc:date.accessioned":["2025-07-10T19:55:01Z"],"dc:date.available":["2025-07-10T19:55:01Z"],"dc:date.issued":["2016-04-20"],"dc:description":["The thesis cover page in the PDF document includes references to Western University’s previous institutional repository platform, known as Scholarship@Western, and links to that platform (beginning with ir.lib.uwo.ca). In citing or referring to this thesis, use the DOI or handle from this page instead. Sample citation: Author name, \"Thesis title.\" (Year). Western University Open Repository. https://doi.org/10.71858/123456."],"dc:description.abstract":["An intramolecular oxime ether cyclopropane annulation developed in 2008 by Kerr has been shown to form 2,5-trans and 2,5-cis pyrrolidines in a stereodivergent fashion. When the oxime ether is functionalized with an enantioenhanced α-hydroxy substitutent and a leaving group, the pyrrolizidine core of (-)-callosine can be accessed in short order. Callosine is a structurally unique pyrrolizidine alkaloid isolated from Mexican flowering plant Senecio callosus. In an effort to complete the total synthesis, the total synthesis of (+)-nemorensic acid, the necic acid component of the callosine, has been established. Attempts at appending the ansa bridge via esterification and macrolactonization are discussed."],"dc:identifier.uri":["https://hdl.handle.net/20.500.14721/33725"],"dc:language.iso":["en_ca"],"dc:publisher":["The University of Western Ontario"],"dc:subject":["nemorensic acid","callosine","total synthesis","cyclopropane","annulation"],"dc:title":["Total Synthesis of (+)-nemorensic acid: En Route to (-)-callosine"],"dc:type":["thesis"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_name":["M Sc"]},"updated_at":"2026-07-27T21:55:54Z"}