{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22024"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22024","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"The condensation of alpha,beta-unsaturated orthoesters and activated ketones: A stereoselective crotonate Michael equivalent","abstract":"U of I Only","abstract_html":"U of I Only","abstract_has_math":false,"creators":["Wolk, Martin Benson"],"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":"2011-05-07T13:26:32Z","date_published":"2011-05-07T13:26:32Z","updated_at":"2026-07-22T22:25:19Z","subjects":["Chemistry, Organic"],"languages":["eng"],"rights":["Copyright 1990 Wolk, Martin Benson"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9026355","(UMI)AAI9026355"],"render_values":[{"text":"AAI9026355","href":null,"code":true},{"text":"(UMI)AAI9026355","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22024","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":["Wolk, Martin Benson"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:26:32Z","10000-01-01","1990"]},{"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 1990 Wolk, Martin Benson"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9026355","(UMI)AAI9026355","http://hdl.handle.net/2142/22024"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["U of I Only","The acid-catalyzed condensation of $(E)$-triethyl orthocrotonate, (Z)-triethyl orthocrotonate, and triethyl orthoacrylate with activated ketones at 25-100$\\sp\\circ$C followed by hydrolysis gave a series of $\\delta$-keto ester adducts. The process is acid-catalyzed and occurs readily with cyclic and acyclic ketones containing an electron-withdrawing group $\\alpha$ to the ketone carbonyl. The general trend in reactivity with respect to the substituents is: RCHO $>$ RCN $>$ RNO$\\sb2$ $\\gg$ RCOMe $>$ RCO$\\sb2$R with cyclopentanones reacting faster than the corresponding cyclohexanones.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)","The syn stereochemistry of three condensation products has been proven by independent synthesis, X-ray crystallographic analysis, and NMR analysis of trans-fused lactones obtained by sodium borohydride reduction. The net reaction of the rearrangement-hydrolysis is the diastereoselective (typically $>$80:20) synthesis of a 1,5-dicarbonyl compound from a ketone (donor) and an unsaturated orthoester (acceptor) equivalent to a Michael addition via a Claisen rearrangement.","The mechanism for the orthoester condensation most likely consists of a series of equilibria involving the reversible, acid-catalyzed formation of an oxonium ion from the $\\alpha$,$\\beta$-unsaturated orthoester, reversible complexation of the oxonium ion with ketone, proton loss, (3,3) sigmatropic rearrangement, and reversible acid-catalyzed orthoester formation. The reaction is not a standard catalytic Michael addition since no reaction was observed under orthoester condensation conditions when ethyl crotonate was substituted for the orthoester.","The stereochemistry of the condensation is proposed to arise from a rapid, diastereoselective Claisen rearrangement of an allyl vinyl orthoester intermediate. The proven stereochemistry of three orthoester condensation products is consistent with a chair transition state.","Made available in DSpace on 2011-05-07T13:26:32Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9026355.pdf: 5395442 bytes, checksum: 0b85df455270c7477ed24ed076c0a85b (MD5) Previous issue date: 1990","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:54:48Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:30-05:00 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":["The condensation of alpha,beta-unsaturated orthoesters and activated ketones: A stereoselective crotonate Michael equivalent"]}]}],"canonical_facts":{"dc:contributor":["Coates, Robert M."],"dc:creator":["Wolk, Martin Benson"],"dc:date":["2011-05-07T13:26:32Z","10000-01-01","1990"],"dc:description":["U of I Only","The acid-catalyzed condensation of $(E)$-triethyl orthocrotonate, (Z)-triethyl orthocrotonate, and triethyl orthoacrylate with activated ketones at 25-100$\\sp\\circ$C followed by hydrolysis gave a series of $\\delta$-keto ester adducts. The process is acid-catalyzed and occurs readily with cyclic and acyclic ketones containing an electron-withdrawing group $\\alpha$ to the ketone carbonyl. The general trend in reactivity with respect to the substituents is: RCHO $>$ RCN $>$ RNO$\\sb2$ $\\gg$ RCOMe $>$ RCO$\\sb2$R with cyclopentanones reacting faster than the corresponding cyclohexanones.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)","The syn stereochemistry of three condensation products has been proven by independent synthesis, X-ray crystallographic analysis, and NMR analysis of trans-fused lactones obtained by sodium borohydride reduction. The net reaction of the rearrangement-hydrolysis is the diastereoselective (typically $>$80:20) synthesis of a 1,5-dicarbonyl compound from a ketone (donor) and an unsaturated orthoester (acceptor) equivalent to a Michael addition via a Claisen rearrangement.","The mechanism for the orthoester condensation most likely consists of a series of equilibria involving the reversible, acid-catalyzed formation of an oxonium ion from the $\\alpha$,$\\beta$-unsaturated orthoester, reversible complexation of the oxonium ion with ketone, proton loss, (3,3) sigmatropic rearrangement, and reversible acid-catalyzed orthoester formation. The reaction is not a standard catalytic Michael addition since no reaction was observed under orthoester condensation conditions when ethyl crotonate was substituted for the orthoester.","The stereochemistry of the condensation is proposed to arise from a rapid, diastereoselective Claisen rearrangement of an allyl vinyl orthoester intermediate. The proven stereochemistry of three orthoester condensation products is consistent with a chair transition state.","Made available in DSpace on 2011-05-07T13:26:32Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9026355.pdf: 5395442 bytes, checksum: 0b85df455270c7477ed24ed076c0a85b (MD5) Previous issue date: 1990","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:54:48Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:25:30-05:00 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":["AAI9026355","(UMI)AAI9026355","http://hdl.handle.net/2142/22024"],"dc:language":["eng"],"dc:rights":["Copyright 1990 Wolk, Martin Benson"],"dc:subject":["Chemistry, Organic"],"dc:title":["The condensation of alpha,beta-unsaturated orthoesters and activated ketones: A stereoselective crotonate Michael equivalent"],"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":"2026-07-22T22:25:19Z"}