{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/19629"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/19629","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Total synthesis of 9,10-syn copalol, an intermediate in the biosynthesis of 9,10-syn diterpenes","abstract":"U of I Only","abstract_html":"U of I Only","abstract_has_math":false,"creators":["Yee, Nathan Kwok Nang"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Coates, Robert M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T12:13:32Z","date_published":"2011-05-07T12:13:32Z","updated_at":"2026-07-22T22:25:14Z","subjects":["Chemistry, Organic"],"languages":["eng"],"rights":["Copyright 1991 Yee, Nathan Kwok Nang"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9136774","(UMI)AAI9136774"],"render_values":[{"text":"AAI9136774","href":null,"code":true},{"text":"(UMI)AAI9136774","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/19629","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Coates, Robert M."]},{"key":"dc:creator","label":"Author","values":["Yee, Nathan Kwok Nang"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T12:13:32Z","10000-01-01","1991"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Chemistry, Organic"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1991 Yee, Nathan Kwok Nang"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9136774","(UMI)AAI9136774","http://hdl.handle.net/2142/19629"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["U of I Only","A total synthesis of 9,10-syn copalol (181) from silyl phosphonate 76 was accomplished in 11 steps with an overall yield of 6.6% (Scheme 54). The key transformation involved electrophilic cyclization of epoxy silyl triene 158 to construct the 9,10-syn bicyclic nucleus with the exocyclic methylene group in 181. The cyclization of 158 afforded a mixture of 9,10-syn- and 9,10-anti isomers 166 and 167 which were separated by preparative HPLC. A mechanism, involving an early transition state for the allyl silane ring closure step is proposed to rationalize type low stereo-selectivity observed in the cyclizations of the epoxy silanes. In the course of this synthesis, procedures were developed for direct C$\\sb{10}$-C$\\sb{10}$ Biellmann coupling of epoxy sulfone 155 and allylic bromide 103, and subsequent regioselective reduction with lithium in EtNH$\\sb2$-Et$\\sb2$O.","Tritium-labelled 9,10-syn CPP (222), ent-CPP (224), (E,Z,E)-GGPP (226), and (E,E,E)-GGPP (228) were prepared and tested as intermediates in the biosynthesis of 9,10-syn diterpene. Preliminary results, obtained in the laboratory of Professor West at UCLA, from the incubations of these substrates with cell-free enzyme extracts from elicited rice tissue (Oryza sativa vc Shesheniski) demonstrated that 9,10-syn CPP is efficiently incorporated into a hydrocarbon presumed to be 9$\\beta$H-pimara-7,15-diene (17), the biosynthetic precursor for the momilactone phytoalexins. In addition, (E,E,E)-GGPP, and not (E,Z,E)-GGPP, proved to be the acyclic substrate for the diterpene cyclase that produced 9,10-syn CPP. These enzymatic experiments indicate that 9,10-syn pimara-7,15-diene is biosynthesized via a chair-boat cyclization of (E,E,E)-GGPP to give 9,10-syn CPP, followed by an S$\\sb{\\rm N\\sp\\prime}$ cyclization to form the C-ring.","Made available in DSpace on 2011-05-07T12:13:32Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9136774.pdf: 8242287 bytes, checksum: a7ec928a1dbdc54148501594875532df (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:38:20Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:15:58-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission"]},{"key":"dc:title","label":"Title","values":["Total synthesis of 9,10-syn copalol, an intermediate in the biosynthesis of 9,10-syn diterpenes"]}]}],"canonical_facts":{"dc:contributor":["Coates, Robert M."],"dc:creator":["Yee, Nathan Kwok Nang"],"dc:date":["2011-05-07T12:13:32Z","10000-01-01","1991"],"dc:description":["U of I Only","A total synthesis of 9,10-syn copalol (181) from silyl phosphonate 76 was accomplished in 11 steps with an overall yield of 6.6% (Scheme 54). The key transformation involved electrophilic cyclization of epoxy silyl triene 158 to construct the 9,10-syn bicyclic nucleus with the exocyclic methylene group in 181. The cyclization of 158 afforded a mixture of 9,10-syn- and 9,10-anti isomers 166 and 167 which were separated by preparative HPLC. A mechanism, involving an early transition state for the allyl silane ring closure step is proposed to rationalize type low stereo-selectivity observed in the cyclizations of the epoxy silanes. In the course of this synthesis, procedures were developed for direct C$\\sb{10}$-C$\\sb{10}$ Biellmann coupling of epoxy sulfone 155 and allylic bromide 103, and subsequent regioselective reduction with lithium in EtNH$\\sb2$-Et$\\sb2$O.","Tritium-labelled 9,10-syn CPP (222), ent-CPP (224), (E,Z,E)-GGPP (226), and (E,E,E)-GGPP (228) were prepared and tested as intermediates in the biosynthesis of 9,10-syn diterpene. Preliminary results, obtained in the laboratory of Professor West at UCLA, from the incubations of these substrates with cell-free enzyme extracts from elicited rice tissue (Oryza sativa vc Shesheniski) demonstrated that 9,10-syn CPP is efficiently incorporated into a hydrocarbon presumed to be 9$\\beta$H-pimara-7,15-diene (17), the biosynthetic precursor for the momilactone phytoalexins. In addition, (E,E,E)-GGPP, and not (E,Z,E)-GGPP, proved to be the acyclic substrate for the diterpene cyclase that produced 9,10-syn CPP. These enzymatic experiments indicate that 9,10-syn pimara-7,15-diene is biosynthesized via a chair-boat cyclization of (E,E,E)-GGPP to give 9,10-syn CPP, followed by an S$\\sb{\\rm N\\sp\\prime}$ cyclization to form the C-ring.","Made available in DSpace on 2011-05-07T12:13:32Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9136774.pdf: 8242287 bytes, checksum: a7ec928a1dbdc54148501594875532df (MD5) Previous issue date: 1991","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:38:20Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:15:58-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission"],"dc:identifier":["AAI9136774","(UMI)AAI9136774","http://hdl.handle.net/2142/19629"],"dc:language":["eng"],"dc:rights":["Copyright 1991 Yee, Nathan Kwok Nang"],"dc:subject":["Chemistry, Organic"],"dc:title":["Total synthesis of 9,10-syn copalol, an intermediate in the biosynthesis of 9,10-syn diterpenes"],"dc:type":["text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:14Z"}