DOCSLIB.ORG

A Mechanistic Investigation of the Photochemistry of 4,4-Dimethyl-2-Cyclohexenone Tad Harbison Koch Iowa State University

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A Mechanistic Investigation of the Photochemistry of 4,4-Dimethyl-2-Cyclohexenone Tad Harbison Koch Iowa State University Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1968 A mechanistic investigation of the photochemistry of 4,4-dimethyl-2-cyclohexenone Tad Harbison Koch Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Koch, Tad Harbison, "A mechanistic investigation of the photochemistry of 4,4-dimethyl-2-cyclohexenone " (1968). Retrospective Theses and Dissertations. 3484. https://lib.dr.iastate.edu/rtd/3484 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. This dissertation has been microfihned exactly as received 69-4251 KOCH, Tad Harbison, 1943- A MECHANISTIC INVESTIGATION OF THE PHOTOCHEMISTRY OF 4,4-DIMETHYL-2- CYCLOHEXENONE. Iowa State University, Ph.D., 1968 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan A MECHANISTIC INVESTI CATION OF THE I'llO'J'OCIlEMlSTKY OF 4,4-DIMETHYl,-2-CYCLOHEXENONE by Tad Harbison Koch A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Organic Chemistry Approved ; Signature was redacted for privacy. In Charge of Major Work Signature was redacted for privacy. Hea'd of Major Department Signature was redacted for privacy. aduate College Iowa State University Of Science ana 'echnology Ames, ïowa 1968 11 TABLE OF CONTENTS Page VITA ix INTRODUCTION 1 REVIEW OF LITERATURE 4 Photochemical Reactions of Some Pertinent Cyclic 4 a,^-Unsaturated Ketones Dimerization 4 Olefin cycloaddition 10 Oxetane formation 16 Rearrangement 18 Photoreactions of some a,3-unsaturated ketones 25 with solvent Recent Reports of Photochemical Processes Resulting 31 from Upper Excited States RESULTS AND DISCUSSION 41 Qualitative Investigation of the Photochemistry of 41 4,4-Dimethyl-2-cyclohexenone Photocycloaddition 41 Photorearrangement and photoreduction 68 Quantitative Investigation of the Photochemistry of 69 4,4-Dimethyl-2-cyclohexenone SUMMARY 133 EXPERIMENTAL 135 Instruments and Methods for Qualitative Study 135 Purification of Reagents 135 Preparative Photocycloaddition and Photorearrangement 337 Initial Irradiation of 1,1-dimethoxyethylene and 137 4,4-dimethyl-2-cyclohexenone in hexane solution Preparative irradiation of 4,4-dimethyl-2-cyclohexenone 139 and 1,1-dimethoxyethylene in hexane Preparative rearrangement and photoreduction in 141 isopropyl alcohol iii Page Structure Proof of Photoproducts 142 Catalytic hydrogénation of 4,4-dimethy1-2- 142 cyclohexenone Pyrolysis of oxetane 143 Hydrolysis of cis-5,5-dimethyl-7,7-dimethoxy- 143 bicyclo[4.2.0]octan-2-one Deuteration of 5,5-dimethylbicyclo[4.2.0]octa-2,7- 144 dione Isomerization of tmns-5,5-dimethyl-7, 7-dimethoxy- 145 bicyclo[4.2.0]octan-2-one to o%8-5,5-dimethyl- 7, 7-diniethoxybicyclo [4.2.0]octan-2-one Wolff-Klshner reduction of ctg-5,5-dimethyl-7,7- 145 dimethoxybicyclo[4.2.0]octan-2-one Baeyer-Villiger oxidation of cis-S,5-diraethyl- 147 bicyclo[4.2.0]octan-2-one Lithium aluminum hydride reduction of yl^ctone ^ ,8 Jones oxidation of cis-2,2-dimethyl-6- .49 (3-hydroxye thy1)-cyclohexanol Es terification of 2-k.eto-3, 3-dimethylcyclohexyl 150 acetic acid Synthesis of ethyl (2-keto-3,3-dimethylcyclohexyl)- 151 acetate Instruments and Methods for Quantitative Study 152 Rotating photochemical apparatus 152 Linear quantum yield apparatus I 153 Linear quantum yield apparatus II 153 Cells used for quantum yield measurements 154 Actinometry 155 Calibration of light intensity of linear quantum 156 yield apparatus II Preparation of samples for quantum yield experiments 157 Analytical procedure 160 Symbols used in tables of data 160 Correction of data 161 Plots of quantum yield data 162 Quantitative Study of Photocycloaddition and 162 Photorearrangement Absolute quantum yield of rearrangement in t-butyl 162 alcohol Effect of solvent on rearrangement 163 Quenching of photorearrangement of 4,4-dimethyl-2- 165 cyclohexenone by di-tertiarybutyl nitroxide Rearrangement in the presence of ferric di^valoyl 166 methane i V Page Data for plot of reciprocal quantum yield versus 167 reciprocal of olefin concentration for photo- cycloaddition in hexane Absolute quantum yield of photocycloaddition 167 in hexane Data for plot of reciprocal of quantum yield versus 168 reciprocal of olefin concentration for photo­ cycloaddition in benzene Photocycloaddition and photorearrangemenc as a function 170 of olefin concentration in t-butyl alcohol Quenching of photocycloaddition in hexane by di-t- 171 butyl nitroxide Quenching photocycloaddition in hexane by oxygen 172 Photocycloaddition in the presence of biacetyl 172 Photocycloadditoon in the presence of 1,3-cyclohexadiene 173 Photocycloaddition in the presence of naphthalene 174 Photocycloaddition in the presence of 1-methyl- 175 naphthalene Photocycloaddition in the presence of p-terphenyl 175 Quenching photocylcoaddition and rearrangement by 176 di-é-butyl nitroxide in t-butyl alcohol Sensitization of photocycloaddition by triphenylamine 177 and phenanthrene Sensitization of photocycloaddition by triphenylene and 177 thioxanthone Sensitization of photocycloaddition by Michler's ketone 178 The effect of temperature on photocycloaddition and 179 pho tor ear rangement Relative sensitized quantum yield of photocycloaddition 179 of 1,1-dimethoxyethylene to isophorone and 4,4-dimethyl-2-cyclohexenone Determination of the stability of di-t-butyl nitroxide 181 Determination of cycloadduc't stability 181 Absence oF ground state complexing 182 lilBLlOCI^PllY 183 ACKNOWLEDCMliNTS 189 APPENDIX 190 V LIST OF FIGURES Page Figure 1. Energy level diagrams 37 Top - 9-anthraldehyde Bottom - anthracene Figure 2. Destruction of 4,4-dimethyl-2-cyclohexenone and 44 formation of photocycloadducts as a function of time Figure 3. Infrared spectra 46 Top - 3,3-dimethoxy-7,7-dimethyl-l-oxaspiro- [3.5]non-5-ene Middle - 6'is-5,5-dimethyl-7, 7-dimethoxybicyclo- [4.2.0]oc tan-2-one Bottom - 6ra%8-5,5-dlmethyl-7,7-dimethoxybicyclo- [4.2.0]oc tan-2-one Figure 4. Nuclear magnetic resonance spectra 48 Top - 3,3-dimethoxy-7,7-dimethyl-l-oxaspiro- [3.5]non-5-ene Middle - cis-5,5-dimethyl-7,7-dimethoxybicyclo- [4.2.0]oc tan-2-one Bottom - trans-5,5-dimethyl-7,7-dimethoxybicyclo- [4.2.0]oc tan-2-one Figure 5. Mass spectra 50 Top - 3,3-dimethoxy-7,7-dimethyl-l-oxaspiro- [3.5]non-5-ene Middle - cis-5,5-dimethyl-7,7-dlmethoxybicyclo- [4.2.0]octan-2-one Bottom - #ra%8-5,5-dimethyl-7,7-dimethoxyblcyclo- [4.2.0]oc tan-2-one Figure 6. Structure proof of ds- and trons-S,5-dimethyl-7,7- 57 dimethoxybicyclo[4.2.0]octan-2-ones Figure 7. Infrared spectra 59 Top - cis-5,5-dimethylbicyclo[4.2.Ojocta- 2,7-dione Middle - cis-5,5-dimethylbicyclo[4.2.0]octan- 7-one Bottom - eis-2,2-dimethyl-9-oxabicyclo[4.3.0]- nonan-8-one Figure 8. Mass spectra 61 Top - eis-5,5-dimethylbicyclo[4.2.0]octa-2,7-dione Middle - cis-S,5-dimethylbicyclo[4.2.0]octan-7-one Bottom - c?is-2,2-dimethyl-9-oxabicyclo[4.3.0]- nonan-8-one VI Page Figure 9. Infrared spectra 63 Top - cis-2,2-dimethyl-6-(3-hydroxyethyl)- cyclohexanol Middle - 2-keto-3,3-diinethylcyclohexyl acetic acid Bottom - ethyl (2-keto-3,3-dimethylcyclohexyl)- acetate Figure 10. Mass spectra 65 Top - Gv'a-2,2-diinethyl-6-(3-hydroxyethyl)- cyclohexanol Middle - 2-keto-3,3-dimethylcyclohexyl acetic acid Bottom - ethyl (2-keto-3,3-dimethylcyclohexyl)- acetate Figure 11. The effect of temperature on the quantum yield of 74 photorearrangement Figure 12. Plot of reciprocal of total quantum yield of 77 photocycloaddition versus reciprocal of olefin concentration in hexane Figure 13. Plots of reciprocal of quantum yield of formation 79 of photocycloadducts versus reciprocal of olefin concentration in hexane Figure 14. Plot of reciprocal of total quantum yield of 81 photocycloaddition versus reciprocal of olefin concentration in benzene Figure 15. Plots of reciprocal of quantum yield of formation of 83 photocycloadducts versus reciprocal of olefin concentration in benzene Figure 16. Stern-Volmer plot for quenching photorearrangement 88 by di-t-butyl nitroxide in t-butyl alcohol Figure 17. A one triplet mechanism for photocycloaddition and 91 photorearrangement Figure 18. Quantum yield relationships for the one triplet 93 mechanism in Figure 17 Figure 19. Stern-Volmer plot for quenching photocycloaddition 98 by di-t-butyl nitroxide in hexane Figure 20. Stern-Volmer plots for quenching formation of 100 photocycloadducts by di-i-butyl nitroxide in hexane vii Page Figure 21. Stern-Volmer plots for quenching formation of 104 photocycloadducts and photorearrangement products by di-t-butyl nitroxide in t-butyl alcohol Figure 22. Plot of reciprocal of the quantum yield of 106 photorearrangement versus olefin concentration in t-butyl alcohol Figure 23. Plots of reciprocal of quantum yield of formation 108 of photocycloadducts versus reciprocal of olefin concentration in t-butyl alcohol Figure 24. A three triplet mechanism for photocycloaddition 110 and photorearrangement Figure 25. Quantum yield relationships for the three triplet 112 mechanism in Figure 24 Figure 26. An energy level diagram of 4,4-dimethyl-2- 119 cyclohexenone Figure 27. A mechanism for photocycloaddition and 125 photorearrangement from excimers Figure 28. A calibration plot of linear quantum yield 159 apparatus II vil I LIST OF TABLES Page Table 1. Effect of solvent on the quantum yield of 71 photocycloaddition Table 2. Quenching of photocycloaddition 101 Table 3. Preparative photocycloaddition as a function 140 of time Table 4. Distillation of photocycloadducts 140 Table 5. Effect of solvent on photorearrangement 164 Table 6. Quenching photorearrangement by di-t-butyl 166 nitroxide Table 7.
Load more

Recommended publications
  • Transition Metal Complexes of Dicyanoacetylene
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1971 Transition Metal Complexes of Dicyanoacetylene: a Study of the Reaction Chemistry of Low Valence States of the Transition Metals, Platinum, Palladium, Nickel, Rhodium, and Iridium. Gregory Lloyd Mcclure Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Mcclure, Gregory Lloyd, "Transition Metal Complexes of Dicyanoacetylene: a Study of the Reaction Chemistry of Low Valence States of the Transition Metals, Platinum, Palladium, Nickel, Rhodium, and Iridium." (1971). LSU Historical Dissertations and Theses. 2001. https://digitalcommons.lsu.edu/gradschool_disstheses/2001 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. 71-29,382 McCLURE, Gregory Lloyd, 1993- TRANSITION METAL COMPLEXES OF DICYANOACETYLENE: A STUDY OF THE REACTION CHEMISTRY OF LOW VALENCE STATES OF THE TRANSITION METALS, PLATINUM, PALLADIUM, NICKEL, RHODIUM, AND IRIDIUM. The Louisiana State University and Agricultural and Mechanical College, Ph.D., 1971 C hem i stry, inorgan ic University Microfilms, A XEROX Company , Ann Arbor. Michigan THIS DISSERTATION HAS BEEN MICROFILMED EXACTLY AS RECEIVED TRANSITION
    [Show full text]
  • Synthesis and Transformations of a Few 9-(Pent-4-Yn-1-Yl)Anthracene-Type Systems
    The Free Internet Journal Paper for Organic Chemistry Archive for Arkivoc 2018, part vii, 0-0 Organic Chemistry Synthesis and transformations of a few 9-(pent-4-yn-1-yl)anthracene-type systems Eason M. Mathew, Tomson Devassia, Sreedharan Prathapan, and Perupparampil A. Unnikrishnan* Department of Applied Chemistry, CUSAT, Kochi-22, India Email: [email protected] Received 05-24-2018 Accepted 11-04-2018 Published on line 12-27-2018 Abstract 9-(Pent-4-yn-1-yl)anthracene-type compounds can potentially undergo intramolecular Diels-Alder (IMDA) reaction to form 9,11-annulated dibenzobarrelenes. Herein we report the synthesis and IMDA reactions of several heteroatom incorporated 9-(pent-4-yn-1-yl)anthracene-type compounds. Keywords: Dibenzobarrelenes, Intramolecular Diels-Alder (IMDA) reaction, tethered barrelenes, fused-ether, ester, sulfide and sulfone, 1H and 13C NMR DOI: https://doi.org/10.24820/ark.5550190.p010.637 Page 1 ©ARKAT USA, Inc Arkivoc 2018, part vii, 0-0 Mathew, E. M. et al. Introduction Synthesis of bicyclo[2,2,2]octa-2,5,7-triene (barrelene) was first reported by Zimmerman1 et al in 1960. Its barrel-shaped array of molecular orbitals and three ethylene units that are like staves attached to the two methine units attracted the attention of chemists. Synthesis of several barrelene derivatives, especially dibenzobarrelenes, exploited Diels-Alder reaction.2-7 Intramolecular Diels-Alder (IMDA) reaction of suitably substituted anthracenes to give tricyclic systems that may be regarded as annulated barrelenes was first reported by Meek and Dann.8,9 In 1980, Ciganek5 reported a systematic investigation on the synthesis of 9,11- bridged dibenzobarrelene via IMDA reaction (Scheme 1).
    [Show full text]
  • Propellane Units: Extension of Triptindane Chemistry
    Canadian Journal of Chemistry A Cyclopenta[hi]acephenanthrylene Bearing Two Benzoannelated [3.3.3]Propellane Units: Extension of Triptindane Chemistry Journal: Canadian Journal of Chemistry Manuscript ID cjc-2016-0498.R1 Manuscript Type: Article Date Submitted by the Author: 12-Nov-2016 Complete List of Authors: Hackfort, Thorsten; Universitat Bielefeld Neumann, DraftBeate; Universitat Bielefeld, Department of Chemistry Stammler, Hans-Georg; Universitat Bielefeld, Department of Chemistry Kuck, Dietmar; Universitat Bielefeld, Department of Chemistry polycyclic aromatic hydrocarbons, phenanthrenes, propellanes, McMurry Keyword: reaction, cyclodehydrogenation https://mc06.manuscriptcentral.com/cjc-pubs Page 1 of 28 Canadian Journal of Chemistry A Cyclopenta[ hi ]acephenanthrylene Bearing Two Benzoannelated [3.3.3]Propellane Units: Extension of Triptindane Chemistry Thorsten Hackfort, [a] Beate Neumann, [a] Hans-Georg Stammler [a] and Dietmar Kuck [a,b] * [a] [b] Department of Chemistry and Center of Molecular Materials (CM 2), Bielefeld University, Universitätsstraße 25, 33615 Bielefeld, Germany Draft *E-mail: [email protected] Tel.: +0049 521 106 2060 Fax: +0049 521 106 6146 Dedicated to Professor Reginald H. Mitchell https://mc06.manuscriptcentral.com/cjc-pubs Canadian Journal of Chemistry Page 2 of 28 - 2 - Abstract. The McMurry reaction of triptindan-9-one (2), a three-fold benzoannelated Cs-symmetrical [3.3.3]propellane ketone, gave trans -9,9’-bitriptindanylidene ( 5), a sterically crowded stilbene hydrocarbon bearing two E-oriented triptindane moieties, in good yield. Photoisomerization of 5 generated the corresponding cis -stilbene 8 in a photostationary E/Z-mixture (55 : 45), which adopts a similarly crowded C2- symmetrical conformation that is apparently static on the NMR timescale. Photocyclodehydrogenation of 5 via 8 in benzene solution afforded the title hydrocarbon 6, a 1,2,9,10-tetrahydrocyclopenta[ hi ]acephenanthrylene merged with two triptindane units, in 85% yield.
    [Show full text]
  • Iificrlgan STATE L'rwebseey Tsuyoghi Kakihama 1966
    SYNTRESIES Aflfi AC LE CATALYZED REA RRARGEMEMT @F M GHQ“ 52$..BESI'EWTEB F: {CYCLG' ($2.25.) OCIA- 5 , '1’ . D iEN - 2. .. 0L3 Tit-tests {fort- {’{m Deqm 3% M . 5. iifiCRlGAN STATE L‘RWEBSEEY Tsuyoghi Kakihama 1966 v7 u“. 2-” ¥ r' LIBRARY ’QTHESIS Michigan State University ABSTRACT SYNTHESIS AND ACID CATALYZED REARRANGEMENT OF HIGHLY SUBSTITUTED BICYCLO[2.2.2]OCTA-5,7-DIEN-2-OLS by Tsuyoshi Kakihana The purpose of this investigation was to synthesize func- tional derivatives of bicyclo[2.2.2]octa-2,5,7-triene ("barrelene") (2). The following scheme was proposed as a route to the desired barrelene derivatives. V R1 H . 2 ‘:TL + R3CECR4'————> AEZ;}//’ 4 \ / R2 R/ R3 R1, R2 = CH3 R3, R4 = "COOCH3 or or R1, R2 = H R3, R4 = ‘CsHS or R3CECR4 = benzyne reductionL acid (OCH /R ——.fi-r—3-> 2 . R4 _ R1 R3 Although this route to barrelenes has thus far been un- successful, various stages of the synthesis have worked Tsuyoshi Kakihana depending on the nature of R groups and a study of these intermediates has led to some unusual rearrangements and bi— and tricyclic systems. Diels-Alder reaction of 3,4,6,6-tetramethylcyclohexa- 2,4-dienone (5) and dimethyl acetylenedicarboxylate gave 3,3,7,8-tetramethyl-5,6-dicarbomethoxybicyclo[2.2.2]octa-5,7- dien-Z-one, 1. 1,5,5,4,7,8-Hexamethyl—5,6-dicarbomethoxybi- cyclo[2.2.2]octa-S,7-dien-2-one, 2, was obtained in a simi- lar manner from 2,3,4,5,6,6-hexamethylcyclohexa-2,4—dienone (4) and dimethyl acetylenedicarboxylate.
    [Show full text]
  • Cheminformatics for Genome-Scale Metabolic Reconstructions
    CHEMINFORMATICS FOR GENOME-SCALE METABOLIC RECONSTRUCTIONS John W. May European Molecular Biology Laboratory European Bioinformatics Institute University of Cambridge Homerton College A thesis submitted for the degree of Doctor of Philosophy June 2014 Declaration This thesis is the result of my own work and includes nothing which is the outcome of work done in collaboration except where specifically indicated in the text. This dissertation is not substantially the same as any I have submitted for a degree, diploma or other qualification at any other university, and no part has already been, or is currently being submitted for any degree, diploma or other qualification. This dissertation does not exceed the specified length limit of 60,000 words as defined by the Biology Degree Committee. This dissertation has been typeset using LATEX in 11 pt Palatino, one and half spaced, according to the specifications defined by the Board of Graduate Studies and the Biology Degree Committee. June 2014 John W. May to Róisín Acknowledgements This work was carried out in the Cheminformatics and Metabolism Group at the European Bioinformatics Institute (EMBL-EBI). The project was fund- ed by Unilever, the Biotechnology and Biological Sciences Research Coun- cil [BB/I532153/1], and the European Molecular Biology Laboratory. I would like to thank my supervisor, Christoph Steinbeck for his guidance and providing intellectual freedom. I am also thankful to each member of my thesis advisory committee: Gordon James, Julio Saez-Rodriguez, Kiran Patil, and Gos Micklem who gave their time, advice, and guidance. I am thankful to all members of the Cheminformatics and Metabolism Group.
    [Show full text]
  • TRIPTYCENE- and BIPHENYLENE-BASED BIFUNCTIONAL LEWIS ACIDS AS ANION RECEPTORS a Dissertation by CHANG-HONG CHEN Submitted to Th
    TRIPTYCENE- AND BIPHENYLENE-BASED BIFUNCTIONAL LEWIS ACIDS AS ANION RECEPTORS A Dissertation by CHANG-HONG CHEN Submitted to the Office of Graduate and Professional Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Chair of Committee, François P. Gabbaï Committee Members, Michael B. Hall Oleg V. Ozerov Melissa A. Grunlan Head of Department, Simon W. North August 2018 Major Subject: Chemistry Copyright 2018 Chang-Hong Chen ABSTRACT The chemistry of main group-based polydentate Lewis acids has drawn considerable attention over the past few decades, owing to application in anion sensing, anion transport, small molecule activation and catalysis. Bidentate Lewis acids featuring the rigid 1,8-naphthalenediyl or ortho-phenylene backbones are the most studied examples of such systems. Owing to the short spacing of the two Lewis acidic sites, these derivatives can only chelate monoatomic anions or polyatomic anions amenable to μ(1,1) ligation. Bearing in mind that this limitation could be overcome through modification of the backbone architecture, we have recently become interested in bidentate Lewis acids with an increased separation between the Lewis acidic centers. It occurred to us that triptycene and biphenylene backbones may offer extended separation between Lewis acidic centers, which may facilitate the selective complexation of larger anions. In this thesis, we report on the chemistry of triptycene- and biphenylene-based diboranes as large-bite bidentate Lewis acids for the μ(1,2) complexation of the cyanide anion as well as hydrazine. The results demonstrate that the biphenylene platform can be used as a support for hybrid ditopic Lewis acids containing both borane and borinic acid moieties.
    [Show full text]
  • Annulenes, Barrelene, Aromatic Ions and Antiaromaticity
    Annulenes, Barrelene, Aromatic Ions and Antiaromaticity Annulenes Monocyclic compounds made up of alternating conjugated double bonds are called annulenes. Benzene and 1,3,5,7-cyclooctatetraene are examples of annulenes; they are named [6]annulene and [8]annulene respectively, according to a general nomenclature system in which the number of pi-electrons in an annulene is designated by a number in brackets. Some annulenes are aromatic (e.g. benzene), but many are not due to non- planarity or a failure to satisfy the Hückel Rule. Compounds classified as [10]annulenes (a Hückel Rule system) serve to illustrate these factors. As shown in the following diagram, 1,3,5,7,9-cyclodecapentaene fails to adopt a planar conformation, either in the all cis-configuration or in its 1,5-trans-isomeric form. The transannular hydrogen crowding that destabilizes the latter may be eliminated by replacing the interior hydrogens with a bond or a short bridge (colored magenta in the diagram). As expected, the resulting 10 π-electron annulene derivatives exhibit aromatic stability and reactivity as well as characteristic ring current anisotropy in the nmr. Naphthalene and azulene are [10]annulene analogs stabilized by a transannular bond. Although the CH2bridged structure to the right of naphthalene in the diagram is not exactly planar, the conjugated 10 π-electron ring is sufficiently close to planarity to achieve aromatic stabilization. The bridged [14]annulene compound on the far right, also has aromatic properties. Barrelene Formulation of the Hückel rule prompted organic chemists to consider the possible aromaticity of many unusual unsaturated hydrocarbons. One such compound was the 6 π- electron bicyclic structure, now known as barrelene.
    [Show full text]
  • Xerox University Microfilms, Ann Arbor,Michigan 48106
    77-2525 VOLZ, William Edward, 1947- STRAINED ALICYCLIC HYDROCARBONS: SYNTHESIS, CHLOROSULFONYL ISOCYANATE ADDITIONS AND ELECTRONIC PROPERTIES. The Ohio State University, Ph.D., 1976 Chemistry, organic Xerox University Microfilms,Ann Arbor, Michigan 48106 STRAINED ALICYCLIC HYDROCARBONS: SYNTHESIS, CHLOROSULFONYL ISOCYANATE ADDITIONS AND ELECTRONIC PROPERTIES DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University by William Edward Volz, B.S. ***** The Ohio State University 1976 ... Reading Committee: Approved by Dr. Leo A. Paquette Dr. Gideon Fraenkel Dr. John S. Swenton Adviser Department of Chemistry DEDICATION Monica, Tracy, and ACKNOWLEDGMENTS I am truly grateful to Professor Leo A. Paquette for his direction, encouragement and enthusiasm during this -work. The stimulating atmo­ sphere provided by the research group he has attracted is something that I am very proud to have experienced. I wish to thank my friend Mike Geekle for all of the nmr work he did for me. I especially value the companionship he gave me and my family. The photoelectron spectra and related molecular orbital calculations are courtesy of Professor Rolf Gleiter and Dr. Peter Bischof at the Tech- nischen Hochschule Damstadt, West Germany. I sincerely appreciate the sacrifices Monica, Tracy and Eric made to my education, and the confidence Monica, my parents and my parents-in-law had in me. I would also like to acknowledge The Ohio State University and the people of Ohio for their financial support. VITA October 15, 1947 ........... B o m - Des Moines, Iowa 1970 .......................... B. S., The Iowa State University, Ames, Iowa 1970-1974.....................
    [Show full text]
  • The Synthesis of Carbacyclic Silanes Via Organosilicon Reactive Intermediates Michael J
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1984 The synthesis of carbacyclic silanes via organosilicon reactive intermediates Michael J. Vuper Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Vuper, Michael J., "The synthesis of carbacyclic silanes via organosilicon reactive intermediates " (1984). Retrospective Theses and Dissertations. 7737. https://lib.dr.iastate.edu/rtd/7737 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS Tliis reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity. 2. When an image on the film is obliterated with a round black mark, it is an indication of either blurred copy because of movement during exposure, duplicate copy, or copyrighted materials that should not have been filmed.
    [Show full text]
  • Bent Bonds (Τ) and the Antiperiplanar Hypothesis the Chemistry of Cyclooctatetraene and Other C8H8 Isomers
    Article Cite This: J. Org. Chem. 2018, 83, 5751−5755 pubs.acs.org/joc Bent Bonds (τ) and the Antiperiplanar HypothesisThe Chemistry of Cyclooctatetraene and Other C8H8 Isomers † ‡ Ghislain Deslongchamps and Pierre Deslongchamps*, † Department of Chemistry, University of New Brunswick, Fredericton, NB, E3B 5A3, Canada ‡ Departement́ de Chimie, UniversitéLaval, Quebec,́ QC, G1 V 0A6, Canada *S Supporting Information ABSTRACT: The bent bond/antiperiplanar hypothesis (BBAH) has been applied to the thermal rearrangements of cyclooctatetraene and related C8H8 isomers. This novel orbital model shows that pyramidal singlet diradical intermediates produced from thermal vibrational states of C8H8 isomers account for their chemical reactivity. ■ INTRODUCTION hyperconjugation5 suggeststhatitispossibletohave τ Cyclooctatetraene (COT) is capable of three fundamental antiperiplanar electronic delocalization involving bonds and that it can be applied to the Diels−Alder reaction,6 [1,3]- structural changes referred to as ring inversion, bond shifting, 7 and valence isomerization1,2 (Figure 1). The first of these sigmatropic alkyl thermal rearrangements, and high-temper- ature isomerization of benzenoid polycyclic aromatic hydro- carbons.8 We have also shown that this model can rationalize the aldol addition reaction of ketones and aldehydes containing an α-alkoxy stereocenter9,10 as well as the important glycosylation step in carbohydrates.9 We wish now to report that the dynamic properties of COT and other C8H8 isomers can also be readily understood through the BBAH as a simple alternative model of structure and reactivity. ■ RESULTS AND DISCUSSION τ-Bond Electronic Delocalization in COT. COT exists in a tub shaped conformation and, based on its description using σ−π bond orbitals, cannot have proper conjugation.
    [Show full text]
  • Microwave-Assisted Synthesis and Reactivity of Porphyrins
    Send Orders for Reprints to [email protected] Current Organic Synthesis, 2014, 11, 89-109 89 Microwave-Assisted Synthesis and Reactivity of Porphyrins Marta Pineiro* Departamento de Química, Universidade de Coimbra, Rua Larga 3004-535 Coimbra, Portugal Abstract: This paper describes past and current microwave-assisted methodologies for the synthesis of porphryins and porphyrin derivatives, including porphyrin precursors such as dipyrromethanes. The review is organized in two main topics, porphyrin synthesis and porphyrin reactivity under microwave irradiation and covers solventless and solution reactions. Keywords: Hydroporphyrin, metalloporphyrin, microwave irradiation, microwave synthesis, porphyrin, tetrapyrrolic macrocycles. 1. INTRODUCTION stituted beta-porphyrins were obtained via cyclisation of linear The acknowledgement that porphyrins and related compounds tetrapyrroles, b-bilenes and a,c-biladienes [15] could be referred. had essential functionalities in nature prompted the interest in mul- Microwave-assisted organic chemistry has grown in the last tiple scientific domains, from the deeper comprehension of those decades as a valuable and versatile tool for organic chemists [16]. functions to the investigation of new applications which comprise In general, compared to conventional heating methods, microwave several analytical uses [1], dye-sensitised solar cells [2], molecular heating has been shown to drastically reduce reaction times, in- electronics and non-linear optics [3], sensors of small molecules crease reaction yields and enhance product selectivity, mostly re- such as O2, NO, NH3 or phosphines [4], catalysts in oxidation and ducing undesirable side reaction products. Microwave irradiation is, photo-oxidation reactions [5], and several biological applications in our days, fully recognized as a useful tool for organic synthesis such as photodynamic therapy of cancer, imaging and boron neu- used in multi-step total synthesis [17], medicinal chemistry and tron-capture therapy [6].
    [Show full text]
  • Organic Seminar Abstracts
    1364 SUiMr^e^ L I B RARY OF THE U N IVLRSITY OF ILLINOIS Q.54-7 1964 Return this book on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. University of Illinois Library L161— O-1096 \ Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/organicseminarab1964univ SEMINAR TOPICS Summer Session, 196^ The Reaction of a-Diketones with Trialkyl Phosphites Earl G. Alley 1 The Mechanism of the Wallach Rearrangement David A. Durand 8 -m> Aromatic Oxocarbon Anions ) Monocyclic (CO ; n Thomas P. Doherty 17 Two Novel Unsaturated Bicyclic Systems M. A. Lintner 26 The Structure of Pimaricin Ping Huang 5 l\ The Schmidt Reaction with Ketones Allan C. Buchholz 4l Stable Acyclic Aliphatic Carbonlum Ions D. Druliner 50 Structure and Syntheses in the Caryophyllene Family R. L. Keener 59 Carbon 15 Nuclear Magnetic Resonance Leigh E. Walker 68 P . THE REACTION OF a-DIKETONES WITH TRIALKYL PHOSPHITES .Reported by Earl G. Alley June 24, 1964 Introduction ,, --Interest in the reactions of esters of phosphorous acid with car- bonyl compounds has arisen mainly because the products undergo Arbuzov type rearrange- ments (l). In addition to the reactions of trialkyl phosphites with a-dicarbonyl compounds , which are the subject of this review, the reactions of trialkyl phosphites with alkyl halides, alcohols, aldehydes, ketones and anhydrides have been studied (l). The reactions of trialkyl phosphites with p-quinones give products the structures of which are the subject of controversy (2,3,4) .
    [Show full text]