{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/74730"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/74730","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Investigation of the steric and/or electronic effects associated with the (1,5)-sigmatropic rearrangement of 1-substituted-2,3,4,5-tetraphenyl- 2,4-cyclopentadien-1-ols","abstract":"A series of eight l-substituted-2,3,4,5-tetraphenyl-2,4-cyclopentadien-l-ols were efficiently synthesized by the addition of the appropriate organometallic reagent to tetracyclone. It was determined that the steric and electronic nature of the migrating groups played a predictable role in the [l,5]-sigmatropic rearrangement of these compounds. Electron donating groups increased the rate of migration whereas electron withdrawing substituents were responsible for slowing the migration. Likewise, smaller groups accelerated the rate while bulky groups deterred the migration. Consequently, the experimental evidence supports the originally proposed charge separated transition state. The Michael addition of potassium cyanide to tetracyclone afforded upon protonation a diastereomeric mixture of the cis (kinetic product) and the trans (thermodynamic product) 4-cyano-2,3,4,5-tetraphenyl-2-cyclopenten-l-ones. Finally an efficient synthesis of 2,3,4,5-tetraphenyl-2(1H)-pyridinone (90%) resulted from the acid promoted addition of sodium azide to tetracyclone. The presence of an intermediate bicyclic triazoline eliminated the Schmitt mechanism as a viable reaction pathway.","abstract_html":"A series of eight l-substituted-2,3,4,5-tetraphenyl-2,4-cyclopentadien-l-ols were efficiently synthesized by the addition of the appropriate organometallic reagent to tetracyclone. It was determined that the steric and electronic nature of the migrating groups played a predictable role in the [l,5]-sigmatropic rearrangement of these compounds. Electron donating groups increased the rate of migration whereas electron withdrawing substituents were responsible for slowing the migration. Likewise, smaller groups accelerated the rate while bulky groups deterred the migration. Consequently, the experimental evidence supports the originally proposed charge separated transition state. The Michael addition of potassium cyanide to tetracyclone afforded upon protonation a diastereomeric mixture of the cis (kinetic product) and the trans (thermodynamic product) 4-cyano-2,3,4,5-tetraphenyl-2-cyclopenten-l-ones. Finally an efficient synthesis of 2,3,4,5-tetraphenyl-2(1H)-pyridinone (90%) resulted from the acid promoted addition of sodium azide to tetracyclone. The presence of an intermediate bicyclic triazoline eliminated the Schmitt mechanism as a viable reaction pathway.","abstract_has_math":false,"creators":["Eagan, Robert Lee"],"institution":"Virginia Polytechnic Institute and State University","degree_name":"Ph. D.","degree_level":"doctoral","degree_discipline":"Chemistry","degree_department":"Chemistry","school":null,"contributors":[],"advisors":[],"committee_chairs":["Ogliaruso, Michael A."],"committee_members":["Bell, Harold M.","Kingston, David G. I.","Mason, John G.","Wightman, James P."],"year":1986,"date_issued":"1986","date_published":"1986","updated_at":"2026-07-22T22:20:27Z","subjects":[],"languages":["en_US"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/10919/74730","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Ogliaruso, Michael A."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Bell, Harold M.","Kingston, David G. 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It was determined that the steric and electronic nature of the migrating groups played a predictable role in the [l,5]-sigmatropic rearrangement of these compounds. Electron donating groups increased the rate of migration whereas electron withdrawing substituents were responsible for slowing the migration. Likewise, smaller groups accelerated the rate while bulky groups deterred the migration. Consequently, the experimental evidence supports the originally proposed charge separated transition state. The Michael addition of potassium cyanide to tetracyclone afforded upon protonation a diastereomeric mixture of the cis (kinetic product) and the trans (thermodynamic product) 4-cyano-2,3,4,5-tetraphenyl-2-cyclopenten-l-ones. Finally an efficient synthesis of 2,3,4,5-tetraphenyl-2(1H)-pyridinone (90%) resulted from the acid promoted addition of sodium azide to tetracyclone. The presence of an intermediate bicyclic triazoline eliminated the Schmitt mechanism as a viable reaction pathway."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Ph. D."]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Investigation of the steric and/or electronic effects associated with the (1,5)-sigmatropic rearrangement of 1-substituted-2,3,4,5-tetraphenyl- 2,4-cyclopentadien-1-ols"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Ogliaruso, Michael A."],"dc:contributor.committeemember":["Bell, Harold M.","Kingston, David G. I.","Mason, John G.","Wightman, James P."],"dc:contributor.department":["Chemistry"],"dc:creator":["Eagan, Robert Lee"],"dc:date.accessioned":["2017-01-30T21:24:08Z"],"dc:date.available":["2017-01-30T21:24:08Z"],"dc:date.issued":["1986"],"dc:description.abstract":["A series of eight l-substituted-2,3,4,5-tetraphenyl-2,4-cyclopentadien-l-ols were efficiently synthesized by the addition of the appropriate organometallic reagent to tetracyclone. It was determined that the steric and electronic nature of the migrating groups played a predictable role in the [l,5]-sigmatropic rearrangement of these compounds. Electron donating groups increased the rate of migration whereas electron withdrawing substituents were responsible for slowing the migration. Likewise, smaller groups accelerated the rate while bulky groups deterred the migration. Consequently, the experimental evidence supports the originally proposed charge separated transition state. The Michael addition of potassium cyanide to tetracyclone afforded upon protonation a diastereomeric mixture of the cis (kinetic product) and the trans (thermodynamic product) 4-cyano-2,3,4,5-tetraphenyl-2-cyclopenten-l-ones. Finally an efficient synthesis of 2,3,4,5-tetraphenyl-2(1H)-pyridinone (90%) resulted from the acid promoted addition of sodium azide to tetracyclone. The presence of an intermediate bicyclic triazoline eliminated the Schmitt mechanism as a viable reaction pathway."],"dc:description.degree":["Ph. D."],"dc:format.mimetype":["application/pdf"],"dc:identifier.uri":["http://hdl.handle.net/10919/74730"],"dc:language.iso":["en_US"],"dc:publisher":["Virginia Polytechnic Institute and State University"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:title":["Investigation of the steric and/or electronic effects associated with the (1,5)-sigmatropic rearrangement of 1-substituted-2,3,4,5-tetraphenyl- 2,4-cyclopentadien-1-ols"],"dc:type":["Dissertation"],"dc:type.dcmitype":["Text"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Ph. D."],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:27Z"}