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Novel Pericyclic Routes to Strained Organic Molecules: Theoretical and Experimental Studies

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Novel Pericyclic Routes to Strained Organic Molecules: Theoretical and Experimental Studies University of New Hampshire University of New Hampshire Scholars' Repository Doctoral Dissertations Student Scholarship Winter 1997 Novel pericyclic routes to strained organic molecules: Theoretical and experimental studies Alexander Zak Bradley University of New Hampshire, Durham Follow this and additional works at: https://scholars.unh.edu/dissertation Recommended Citation Bradley, Alexander Zak, "Novel pericyclic routes to strained organic molecules: Theoretical and experimental studies" (1997). Doctoral Dissertations. 1987. https://scholars.unh.edu/dissertation/1987 This Dissertation is brought to you for free and open access by the Student Scholarship at University of New Hampshire Scholars' Repository. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of University of New Hampshire Scholars' Repository. For more information, please contact [email protected]. INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality i illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely afreet reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy for an additional charge. Contact UMI directly to order. UMI A Bell & Howell Information Company 300 North Zeeb Road, Arm Arbor MI 48106-1346 USA i 313/761-4700 800/521-0600 i Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. NOVEL PERICYCLIC ROUTES TO STRAINED ORGANIC MOLECULES; THEORETICAL AND EXPERIMENTAL STUDIES BY ALEXANDER ZAK BRADLEY B.S. URSINUS COLLEGE, 1992 DISSERTATION I ? Submitted to the University of New Hampshire in Partial Fulfillment of the Requirements for the Degree of ; Doctor of Philosophy 1 ? in f Chemistry December, 1997 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. UMI Number: 9819670 j UMI Microform 9819670 f Copyright 1998, by UMI Company. All rights reserved. > This microform edition is protected against unauthorized r. copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ABSTRACT NOVEL PERICYCLIC ROUTES TO STRAINED ORGANIC MOLECULES; THEORETICAL AND EXPERIMENTAL STUDIES Alexander Zak Bradley University of New Hampshire, December, 1997 The chemistry of cydobutyne (20) and 1 ,2 -cydobutadiene (21) has been investigated. Research efforts were focused on attempting to independently generate and trap these highly reactive spedes. The trapping experiments were incondusive in each case. Calculations using MCSCF theory indicate that perfluorination of cydobutyne will have a profound effect that stabilizes the cydobutyne relative to rearrangement However, experiments designed to generate and trap £ perfluorocydobutyne (73) did not provide evidence for this compound. i £ The development of new routes to strained organic compounds through the extension of known pericydic reactions is described. These novel pericydic reactions have been investigated by ab initio calculations and flash vacuum pyrolysis (FVP) experiments. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. MP4/6-31GV/MP2/6-31G* calculations support the possibility that strained six-membered rings can be prepared by replacement of a double bond with a triple bond in the prototypical Diels/Alder cycloaddition eq. [1] or electrocyclic reaction eq. [7]. The novel cycloadditions explored involve the replacement of the traditional 1,3-butadiene component of [4 + 2] cycloadditions with vinylacetylene (19), 1,3-butadiyne (160), and strans- butadiene (233). Electrocyclic reactions of 1,2,3-cydohexatriene (167), 1,2,4- cydohexatriene (166), cydohexen-3-yne (247), and 1,2,3,4-cydohexatetraene (243) have been investigated. Experimental evidence is presented for the first example of intramolecular diyne + alkene and diyne + alkyne cydoadditions. The latter process is believed to give an o-benzyne intermediate, which is subsequently j reduced to indan. This cydoaddition is unique in that it may be considered a j j cydoaromatization because an aromatic ring is directly generated. The j | mechanism and generality of diyne cydoadditions is examined. f S * j i\ I it I i i i Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. This dissertation has been examined and approved. ( 1 j u ________ Dissertation Director, Ricfoird P. Johnson Professor of Chemistry W. Rudolf Seitz, iProfessor o f Chemistry and Chemistry Department Chairperson Professor of Chemistry GlejMiller, Assistant Professor of Chemistry Mar fin G. Kodolek, Faculty in Residence Lr as m? J ^ a te Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. DEDICATION This work is dedicated to my entire family. My parents, Walter and Josephine Bradley, received their education by raising seven children. My older siblings (Sharon, Tom, Paul, Anita, Jeanmarie, and Andrea) have collectively and individually taught me lessons that I could never learn in school. For this education, I thank each of you. Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. ACKNOWLEDGEMENTS I would like to thank anyone who has supported me through this endeavor. Clearly, I could have never succeeded without the assistance of others. I sincerely appreciate the support that I have received from my friends and family. Often, it was the small acts of kindness or simple words of encouragement that helped me the most. I wish that I could acknowledge each of you. However, I fear that inevitably I would leave someone out My education has been facilitated by excellent teachers. I would like to acknowledge the dedicated instructors of The Upper Darby School District, Ursinus College, and The University of New Hampshire. I am grateful to any individual or institution that has given me the opportunity to further my education. I would like to acknowledge my advisor Dr. Richard P. Johnson for his guidance. I consider him an excellent research mentor. I appreciate the diverse training that I received as a scientist and an educator. His patience, with this recalcitrant student, has not gone unnoticed. iv Reproduced with permission of the copyright owner. Further reproduction prohibited without permission. TABLE OF CONTENTS DEDICATION................................................................................................................. iii ACKNOWLEDGEMENTS............................................................................................ iv LIST OF SCHEMES.......................................................................................................viii LIST OF FIGURES.........................................................................................................xiii LIST OF TABLES............................................................................................................xv ABSTRACT.....................................................................................................................xvi CHAPTER PAGE GENERAL INTRODUCTION........................................................................................ 1 I. CHEMISTRY OF C4 MOLECULES.................................................................... 2 Introduction to Strained Molecules .......................................................2 C4H 4 Isomers ..............................................................................................8 Cyclic Allenes...........................................................................................14 1,2-Cydobutadiene ( 2 1 )............................................................. 18 ai ^ Results and Discussion .......................................................................... 20 r,f | Attempted Synthesis and Trapping j of 1,2-Cydobutadiene (21) ...................................................... 20 t [ Attempted Thermal/Ground State ! Generation of 1,2 -Cydobutadiene (21) ............................................25 Cyclic Alkynes.........................................................................................28 v Reproduced with permission of the copyright owner. Further reproduction prohibited without permission.
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