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Deuterium Exchange Studies of Some Cyclopentenone Derivatives Robert Logan Myers Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1963 Deuterium exchange studies of some cyclopentenone derivatives Robert Logan Myers Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Myers, Robert Logan, "Deuterium exchange studies of some cyclopentenone derivatives " (1963). Retrospective Theses and Dissertations. 2549. https://lib.dr.iastate.edu/rtd/2549 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 64—3885 microfilmed exactly as received MYERS, Robert Logan, 1937- DEUTERIUM EXCHANGE STUDIES OF SOME CYCLOPENTENONE DERIVATIVES. Iowa State University of Science and Technology Ph.D., 1963 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan DEUTERIUM EXCHANGE STUDIES OF SOME CYCIOPEHTENONE DERIVATIVES Robert Logan Myers 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. Work Signature was redacted for privacy. Head of Major Department Signature was redacted for privacy. Dean Iowa State University Of Science and Technology Ames, Iowa 1963 11 TABLE OF CONTENTS Page INTRODUCTION 1 HISTORICAL 3 DISCUSSION 1Ç EXPERIMENTAL 43 SUMMARY 82 ACKNOWLEDGEMENTS 83 APPENDIX 84 1 INTRODUCTION Synthetic methods for the preparation of highly substi tuted 5-benzylidenecyclopentenones have long been known. -
Elucidating How Wood Adhesives Bond to Wood Cell Walls Using High-Resolution Solution-State NMR Spectroscopy
Elucidating How Wood Adhesives Bond to Wood Cell Walls using High-Resolution Solution-State NMR Spectroscopy Daniel J. Yelle U.S. Forest Service, Forest Products Laboratory Madison, WI, 53726, USA [email protected] Introduction Lignin, 25-30% of wood, is a phenolic polymer made Some extensively used wood adhesives, such as up of branched phenylpropanoid units that are capable of pMDI (polymeric methylene diphenyl diisocyanate) and reacting with other phenols during adhesive bonding. PF (phenol formaldehyde) have shown excellent adhesion Model compound studies have shown that under alkaline properties with wood. However, distinguishing whether conditions and ≥100 °C, β-aryl ether linkages release for- the strength is due to physical bonds (i.e., van der Waals, maldehyde to give vinyl ether linkages (Figure 2a) [10]. London, or hydrogen bond forces) or covalent bonds be- Phenylcourmaran linkages release formaldehyde in a simi- tween the adherend and the adhesive is not fully under- lar fashion to give stilbene linkages (Figure 2b) [10]. 13C stood. Previous studies, where pMDI model compounds NMR spectroscopy showed that most of this released for- were reacted with wood, showed that carbamate (urethane) maldehyde ends up as the methylene bridge between the 5- formation with wood polymers is only possible when: 1. positions on guaiacyl units (Figure 2c) [11]. the number of moles of isocyanate is significantly higher a. HO H O than the moles of water molecules in the wood, 2. high γ γ HO β β α O 4 α β O 4 α O 4 temperatures are used, and 3. the isocyanate-based com- OCH3 OCH - OH 3 OCH3 O + CH pound is of low molecular weight [1]. -
Synthesis, Structure and Attempted Polymerization of a Diepoxide Macrocycle Paul Yarincik Sacred Heart University
Sacred Heart University DigitalCommons@SHU Chemistry & Physics Faculty Publications Chemistry and Physics 10-2012 Synthesis, Structure and Attempted Polymerization of a Diepoxide Macrocycle Paul Yarincik Sacred Heart University Jeffrey H. Glans Sacred Heart University, [email protected] Follow this and additional works at: http://digitalcommons.sacredheart.edu/chem_fac Part of the Polymer Chemistry Commons Recommended Citation Yarincik, Paul and Glans, Jeffrey H., "Synthesis, Structure and Attempted Polymerization of a Diepoxide Macrocycle" (2012). Chemistry & Physics Faculty Publications. 1. http://digitalcommons.sacredheart.edu/chem_fac/1 This Article is brought to you for free and open access by the Chemistry and Physics at DigitalCommons@SHU. It has been accepted for inclusion in Chemistry & Physics Faculty Publications by an authorized administrator of DigitalCommons@SHU. For more information, please contact [email protected]. Letters in Organic Chemistry, 2012, 9, 545-548 545 Synthesis, Structure and Attempted Polymerization of a Diepoxide Macrocycle Paul Yarincik and Jeffrey H. Glans* Department of Chemistry, Sacred Heart University, Fairfield, CT 06825, USA Received October 19, 2011: Revised December 31, 2011: Accepted January 04, 2012 Abstract: A novel diepoxide containing paracyclophane was synthesized by peracid oxidation of a known paracyclo- phane diene. The resulting diepoxide was characterized. It was investigated as a potential monomer for a cyclophane con- taining polyether by cationic ring opening polymerization. None of the standard catalyst systems for such a polymeriza- tion were successful in producing polymer. Keywords: Cationic polymerization, cyclophane, diepoxide, macrocycle. R INTRODUCTION R O O O+ Cationic polymerization of olefins is one of the major R+ routes to high molecular weight polymers [1]. The mecha- O O+ O nism involves nucleophilic attack of the alkene functional group on the electron poor initiator (initiation) or the grow- ing cationic chain end (propagation). -
Or· 8-Annoquriioltlmb WITH. NIT~~~OI,4
BIBIUD.~; TliE REACTION 8-AnNOQuriiOLtlmB WITH. NIT~~~OI,4 •' >'•' • or·I,' ",i. by Hugh Bu:rknla·p.·,:Ilona.hoe B.s.• ,. Rookhurst College, 194.3 M.A.,, Univ&rESi.ty of ICansas, · 1947 . Submitted to the Department of ·chemistry and the Faculty. of. the . G:raduate School or the University of Kansas in partial fulfillment ot the ?'equirements for the de• gree of Doctor ot Philosophy. Advisory Committee · May, 19.$0 AOKNOWLEOOMENT The author wishes to ex.press his thanks and appreciation to Dr. J. H. Burokhalter,, who suggested this problem, and Dr. a. A. Vanderwerf for ·their helpful suggestions and guidance during the course of this work. H.B.D. TABLE OF OONTEN'TS Chapter Page I • THE PROBLE?i Olr MALARIA. A. Introduction • • • • • . • • 1 B. The types of malaria. • • • • • • •• 2 O. The biology of malarial infection • • 3 D. The prophylaxis and treatment of malaria: •. ;•' •. • • •. • . ;.. • • : •••• ·• • • ., 6 II. ·Atfl'IMALARIAL ·:DRUGS. :· • · ,, A. Olassific at ion and. screening of antimalarial drugs • • . ,, . .. ' . • • • • 12 B. Historical • • • • • • • • • • • • • 1~ c. Quinine • .. • • • .. • • • • • • • • • 16 D. Synthetic substitutes • • • • • • • • 19 l. Plasmochin • • • • • .. • • • • • 19 2 •. Quinaorine • • • • • .. • • • • • 21 3. Ohloroquine • • • • • • • • • •• 21 q.. Pentaquine •• • • • • • • • • • 23 s. Paludrine • • • • • • • • • • • • 2q. E. Me(lhanism ot action of antimalarial drugs • • • • • • • •• • • • • • • • 2$ 1. The metabolite-antimetaboli te relationship • • • • • • • •• • 2.$ 2. The quinoid•Quinonimine theory • 26 3. Conclusions • • • • • • • • • •• 28 · -Ohapter III.· THE ANTIMALARIAL PROGRAM 1941-1945 . .A. The overall program • • • • • • • • • 30 .a. :._ Tb(j ·4•aminoquinolinea • • • • • • • • .32 · <h ·. The 8-aminoqu.inolines • : • . • • • • • • 34. IV. • DISCUSSION Of THE PROBLEM ) • • • • • .• • • • .38 ·V. · DISCUSSION OF· RESULTS. · - . A.;, Unsymmetrical hybrids related to '. propanediemine * • • • • •. • • • • • 46 B. ··Symmetrical: hybrida related to prc,pan~di8J1iinet ~d methanediamine • • S2 . -
Nuclear Magnetic Resonance Study of Cyclopentenone and Some of Its Derivatives Charles Edward Lyons Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1961 Nuclear magnetic resonance study of cyclopentenone and some of its derivatives Charles Edward Lyons Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Lyons, Charles Edward, "Nuclear magnetic resonance study of cyclopentenone and some of its derivatives " (1961). Retrospective Theses and Dissertations. 1975. https://lib.dr.iastate.edu/rtd/1975 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 62-1359 microfilmed exactly as received LYONS, Charles Edward, 1929- NUCLEAR MAGNETIC RESONANCE STUDY OF CYCLOPENTENONE AND SOME OF ITS DERIVA TIVES. Iowa State University of Science and Technology Ph.D., 1961 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan NUCISÂR MACBETIC RESONANCE STUDY OF CTCIJDPENTBNONE AHD SOIE OF ITS DERIVATIVES ty Charles Edward Iyons A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHHCSQPHT Major Subject! Organic Chemistry ApprovedJ Signature was redacted for privacy. Signature was redacted for privacy. Signature was redacted for privacy. Iowa State University Of Science and Technology Ames, Iowa 1961 ii TABIE OF CONTENTS Page INTRODUCTION 1 HISTORICAL 2 DISCUSSION 12 SPECTRA 61 EXPERIMENTAL 91 SUMMAHT 96 ACKNOWIEDGEMBNTS 97 APPENDIX 98 1 INTRODUCTION During the past several years progress has been made in exploring the oheaLstiy of eyclopentenone and soma of its derivatives. -
Converting Disulfide Bridges in Native Peptides to Stable Methylene Thioacetals
Chemical Science View Article Online EDGE ARTICLE View Journal | View Issue Converting disulfide bridges in native peptides to stable methylene thioacetals† Cite this: Chem. Sci.,2016,7, 7007 C. M. B. K. Kourra and N. Cramer* Disulfide bridges play a crucial role in defining and rigidifying the three-dimensional structure of peptides. However, disulfides are inherently unstable in reducing environments. Consequently, the development of strategies aiming to circumvent these deficiencies – ideally with little structural disturbance – are highly sought after. Herein, we report a simple protocol converting the disulfide bond of peptides into highly stable methylene thioacetal. The transformation occurs under mild, biocompatible conditions, enabling the conversion of unprotected native peptides into analogues with enhanced stability. The developed Received 23rd May 2016 protocol is applicable to a range of peptides and selective in the presence of a multitude of potentially Accepted 24th July 2016 reactive functional groups. The thioacetal modification annihilates the reductive lability and increases the DOI: 10.1039/c6sc02285e serum, pH and temperature stability of the important peptide hormone oxytocin. Moreover, it is shown www.rsc.org/chemicalscience that the biological activities for oxytocin are retained. Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Introduction disulde bond engineering emerged as an important strategy to improve the metabolic stability of disulde-containing peptides, Peptides have recently been enjoying a renewed interest in whilst maintaining their biological activity. For instance, their application as therapeutic agents.1 They provide a large replacements of the disulde group with a lactam,10 thioether,11 a chemical space with a diverse array of molecular frameworks selenium12 or dicarba13 analogues have been reported.5 Many of for the development of novel therapeutics for a plethora of these methods require signicant modication of the synthetic biomedical applications. -
Recent Progress in the Synthetic Assembly of 2-Cyclopentenones
REVIEW ▌1 Recentreview Progress in the Synthetic Assembly of 2-Cyclopentenones David2-Cyclopentenone J. Synthesis Aitken,*a Hendrik Eijsberg,a,b Angelo Frongia,b Jean Ollivier,a Pier Paolo Pirasb a Laboratoire de Synthèse Organique & Méthodologie, ICMMO (CNRS UMR 8182), Université Paris Sud, 15 rue Georges Clemenceau, 91045 Orsay cedex, France Fax +33(1)69156278; E-mail: [email protected] b Dipartimento di Scienze Chimiche e Geologiche, Università degli studi di Cagliari, Complesso Universitario di Monserrato, S.S. 554, Bivio per Sestu, 09042 Monserrato, Cagliari, Italy Received: 09.07.2013; Accepted after revision: 21.08.2013 considerable number of ways in which the target ring sys- Abstract: An overview of the most important synthetic strategies currently available for the preparation of cyclopent-2-enones is pre- tem can be created from acyclic precursors, in either inter- sented and illustrated with recent applications. molecular or intramolecular mode. Most of the possible disconnection strategies have been examined, and it is im- 1 Introduction portant to recognize that for any given target 2-cyclopen- 2 Multicomponent Ring Assembly tenone, there may be several convenient approaches 3 Cyclizations available. The main approaches for ring construction are 4 Transformations of Existing Cyclic Systems summarized graphically in Figure 1. 5 Miscellaneous Methods O (4+1) O O (3+2) (3+2) coupling 6 Conclusions 1 1 1 5 5 2 5 2 2 RCM Key words: cyclopentenones, cyclization, carbocycles, ring clo- (4+1) (3+2) Rautenstrauch 4 3 4 3 4 3 aldol-type annulation sure, rearrangement, annulation (2+2+1) PKR Nazarov (3+2) Figure 1 The main ring-construction strategies for 2-cyclopente- none synthesis, showing the atom connectivities made during ring as- 1 Introduction sembly (left and center) and cyclization approaches (right). -
Structure and Conformation of Bilirubin
364 C. C. KUENZLE, M. H. WEIBEL AND R. R. PELLONI Kuenzle, C. C. (1970b) Biochem. J. 119, 411-435 Kuenzle, C. C., Weibel, M. H., Pelloni, R. R. & Kuenzle, C. C. (1973) in Metabolic Conjugation andMeta- Hemmerich, P. (1973), Biochem. J. 133, 364-368 bolic Hydrolysis (Fishman, W. H., ed.), vol. 3, Academic von Dobeneck, H. & Brunner, E. (1965) Hoppe-Seyler's Press, New York, in the press Z. Physiol. Chem. 341, 157-166 APPENDIX Structure and Conformation of Bilirubin OPPOSING VIEWS THAT INVOKE TAUTOMERIC EQUILIBRIA, HYDROGEN BONDING AND A BETAINE MAY BE RECONCILED BY A SINGLE RESONANCE HYBRID By CLIVE C. KUENZLE,* MATTHIAS H. WEIBEL,* RENATO R. PELLONI* and PETER HEMMERICHt * Department ofPharmacology and Biochemistry, School of Veterinary Medicine, University ofZurich, CH-8057 Zurich, Switzerland and t Department ofBiology, University ofKonstanz, D-7750 Konstanz, Germany A novel conformational structure of bilirubin is presented which obtains maximum stabilization through a system of four intramolecular hydrogen bonds. Two hydrogen bonds link oxygen and nitrogen atoms of each end ring to the contralateral carboxyl group. The proposed structure can explain a variety of uncommon features of bilirubin, and reconciles many seemingly contradictory hypotheses by accommodating them in individual structures which are mesomeric forms of one resonance hybrid. In the light of this newly conceived structure the following characteristics of bilirubin are re-evaluated: the stability of the compound, its reaction with diazomethane, the conformational beha- viour of its dimethyl ester, its spectral properties, the chirality of the compound when complexed to serum albumin, and the structure of its metal chelates. The basic structure of bilirubin was elucidated by when bilirubin is esterified with diazomethane Fischer's group (Fischer et al., 1941; Fischer & (Kuenzle, 1970a). -
Articles Conformational Analysis of Chirally Deuterated Tunicamycin As an Active Site Probe of UDP-N-Acetylhexosamine:Polyprenol
13248 Biochemistry 2004, 43, 13248-13255 Articles Conformational Analysis of Chirally Deuterated Tunicamycin as an Active Site Probe of UDP-N-Acetylhexosamine:Polyprenol-P N-Acetylhexosamine-1-P Translocases† Lin Xu,‡ Michael Appell,§,| Scott Kennedy,‡ Frank A. Momany,§,| and Neil P. J. Price*,‡,§,⊥ USDA-ARS-NCAUR, Fermentation Biotechnology Research Unit, and Plant Polymer Research Unit, 1815 North UniVersity Street, Peoria, Illinois 61604, and UniVersity of Rochester Medical Center, 601 Elmwood AVenue, Rochester, New York 14642 ReceiVed August 4, 2004; ReVised Manuscript ReceiVed August 19, 2004 ABSTRACT: Tunicamycins are potent inhibitors of UDP-N-acetyl-D-hexosamine:polyprenol-phosphate N-acetylhexosamine-1-phosphate translocases (D-HexNAc-1-P translocases), a family of enzymes involved in bacterial cell wall synthesis and eukaryotic protein N-glycosylation. Structurally, tunicamycins consist of an 11-carbon dialdose core sugar called tunicamine that is N-linked at C-1′ to uracil and O-linked at C-11′ to N-acetylglucosamine (GlcNAc). The C-11′ O-glycosidic linkage is highly unusual because it forms an R/â anomeric-to-anomeric linkage to the 1-position of the GlcNAc residue. We have assigned the 1H and 13C NMR spectra of tunicamycin and have undertaken a conformational analysis from rotating angle nuclear Overhauser effect (ROESY) data. In addition, chirally deuterated tunicamycins produced 2 by fermentation of Streptomyces chartreusis on chemically synthesized, monodeuterated (S-6)-[ H1]glucose have been used to assign the geminal H-6′a, H-6′b methylene bridge of the 11-carbon dialdose sugar, 4 tunicamine. The tunicamine residue is shown to assume pseudo-D-ribofuranose and C1 pseudo-D- galactopyranosaminyl ring conformers. -
Sc-Homoaromaticity
This is a repository copy of Modern Valence-Bond Description of Homoaromaticity. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/106288/ Version: Accepted Version Article: Karadakov, Peter Borislavov orcid.org/0000-0002-2673-6804 and Cooper, David L. (2016) Modern Valence-Bond Description of Homoaromaticity. Journal of Physical Chemistry A. pp. 8769-8779. ISSN 1089-5639 https://doi.org/10.1021/acs.jpca.6b09426 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ Modern Valence-Bond Description of Homoaromaticity Peter B. Karadakov; and David L. Cooper; Department of Chemistry, University of York, Heslington, York, YO10 5DD, U.K. Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K. Abstract Spin-coupled (SC) theory is used to obtain modern valence-bond (VB) descriptions of the electronic structures of local minimum and transition state geometries of three species that have been con- C sidered to exhibit homoconjugation and homoaromaticity: the homotropenylium ion, C8H9 , the C cycloheptatriene neutral ring, C7H8, and the 1,3-bishomotropenylium ion, C9H11. -
(+)-Belactosin A
Total Synthesis of (+)-Belactosin A A thesis submitted by James Nicholas Scutt in partial fulfilment of the requirements for the degree of Doctor of Philosophy TT MU r u * 1630444 Heilbron Laboratory Department of Chemistry Imperial College London London SW7 2AY January 2005 Contents Contents 2 Abstract 4 Acknowledgements 5 Abbreviations 6 Stereochemical notation 9 Chapter 1 - Introduction 10 1.1 Isolation and structure of (+)-belactosin A 11 1.2 Proteasome inhibition 12 1.2.1 Biological activity of (+)-belactosin A 12 1.3 Review of previous work 14 1.3.1 De Meijere's synthesis of(2S/R*, I'R, 2'5)-AcpAla 14 1.3.2 Synthesis of a related (isomeric) p-lactone 20 1.4 Recent synthetic work 22 1.4.1 De Meijere's synthesis of AcpAla (all isomers) 23 1.4.2 Vedaras' synthesis of (2S, 1 'R, 2'S)-AcpAla 25 1.4.3 De Meijere's total synthesis of (+)-belactosin A 26 Chapter 2 - Results and discussion 30 2.1 Project aims 31 2.1.1 Synthesis of trans-AcpAla isomers - overview of synthetic strategy 32 2.2 Boronic ester route 34 2.2.1 Introduction 34 2.2.2 Synthesis of cyclopropyl boronic esters 36 2.2.3 Amination of cyclopropyl boronic esters 39 2.3 Epoxide cyclopropanation route 43 2.3.1 Introduction 43 2.3.2. Stereoselectivity and stereospecificity 47 2.3.3 Wadsworth-Emmons aminocyclopropanation 49 2.3.4 Optimisation of Wadsworth-Emmons cyclopropanation 53 2.3.5 Increasing reactivity 59 2.3.6 Room temperature Wadsworth-Emmons cyclopropanation 62 2.3.7 Horner cyclopropanation 64 2.3.8 Asymmetric Wadsworth-Emmons cyclopropanation 65 2.4 Conversion of cyclopropyl -
The Pauson-Khand Reaction: a Gas-Phase and Solution-Phase Examination Using Electrospray Ionization Mass Spectrometry † † ‡ † Matthew A
ARTICLE pubs.acs.org/Organometallics The Pauson-Khand Reaction: A Gas-Phase and Solution-Phase Examination Using Electrospray Ionization Mass Spectrometry † † ‡ † Matthew A. Henderson, Jingwei Luo, Allen Oliver, and J. Scott McIndoe*, † Department of Chemistry, University of Victoria, P.O. Box 3065, Victoria, British Columbia V8W 3V6, Canada ‡ Department of Chemistry and Biochemistry, University of Notre Dame, 251 Nieuwland Science Hall, Notre Dame, Indiana 46556-5670, United States bS Supporting Information ABSTRACT: A series of dicobalt hexacarbonyl complexes with charged alkyne ligands were prepared to enable the study of the PausonÀKhand reaction using ESI-MS. The hexacarbonyl complexes can be activated in the gas phase through removal of a CO ligand. The resulting pentacarbonyl ions react readily with alkenes, and no discrimina- tion between alkenes was found for this step, indicating that alkene association is not rate determining in the intermolecular reaction. Solution-phase ESI-MS studies on a system set up for intramolecular reactivity revealed only the hexacarbonyl complex as a detectable intermediate, and the reaction was shown to have a large enthalpy and entropy of activation, consistent with ligand dissociation being rate limiting in the reaction. ’ INTRODUCTION rapidly.24 Efforts have been expended to trap or detect later 25 The Pauson-Khand reaction was discovered in 1971 during intermediates. Evans and co-workers were able to crystallize a pentacarbonyldicobalt enyne complex with an (intramolecular) investigations of the reaction of Co2(CO)8 with various simple fi 26 compounds.1,2 Under a high pressure of CO, an alkene, an alkyne, alkene lling the sixth coordination site, but the subsequent and CO were observed to combine in a [2 + 2 + 1] cycloaddition insertion reaction failed.