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Part I. Mechanism of the Thermal Isomerization of 2-Norbomene-5,6-Endodicarboxylic Anhydride. Part II. The Aldoketene Dimer Rearrangement


Baldwin, John Edwin (1963) Part I. Mechanism of the Thermal Isomerization of 2-Norbomene-5,6-Endodicarboxylic Anhydride. Part II. The Aldoketene Dimer Rearrangement. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/83K8-TP73.


NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. PART I The Diels-Alder adduct of cyclopentadiene and maleic anhydride, 2-norbornene-5,6-endo-dicarboxylic anhydride, may be rearranged thermally to its exo-isomer. This isomerization is known to occur in part through an internal mechanistic pathway. In order to study the mechanism of this rearrangement, an attempt was made to synthesize 2-norbornene-5,6-endo-dicarboxylic anhydride stereospecifically labeled with carbon-14 in one carboxyl group, rearrange this material under conditions favoring the internal pathway, and degrade the exo-anhydride in a stereospecific fashion, measuring the carbon-14 activities of each carbonyl group separately. Three synthetic approaches to the stereo specifically labeled endo-anhydride, through the intermediates ethyl cis-[...]-cyanoacrylate, (-)-menthyl hydrogen maleate, and (-)-menthoxymalealdehydic acid, have not been successful. Rearrangement of the endo-anhydride in the presence of tetracyanoethylene gave exo-anhydride from the internal mechanism and 2,2,3,3-tetracyanonorborn-5-ene from the external process. Degradation of 2-norbornene-5,6-exo-dicarboxylic anhydride by hydrogenation and reaction with (-)-menthol gave two diasteromeric (-)-menthyl hydrogen 2,3-exo-norbornanedicarboxylates, whose absolute configurations were established by degradation of one to an optically active 2-exo-norbornanecarboxylic acid. 2,3-Endo-norbornanedicarboxylic anhydride was rearranged to its exo-isomer when heated to 250º for 18 hours. PART II The neutral phenylketene dimer has been synthesized, identified as 3-hydroxy-2,4-diphenyl-3-butenoic lactone, reduced to [...],[...]-diphenylbutyric acid, and rearranged with base to an acidic isomer, tentatively postulated to be 2,4-diphenylcyclobutanedione or 2,4-diphenylcyclobutenolone. Structural assignments for neutral methylketene dimer, acidic methylketene dimer, 3,5-dimethyl-6-ethylpyronone, 3,5-diphenyl-4-hydroxy-6-benzylpyrone, and 3,5-dimethyl-4-hydroxy-6-ethylpyrone have been confirmed or corrected.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:(Chemistry and Physics)
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Minor Option:Physics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Roberts, John D.
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1963
Record Number:CaltechETD:etd-10052005-154306
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3926
Deposited By: Imported from ETD-db
Deposited On:06 Oct 2005
Last Modified:02 Jan 2024 22:18

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