DOCSLIB.ORG

ABSTRACT JANG, YUJIN. Synthesis of 1-Sulfonylcyclopropanols and Their Application in New Chemical Transformations As Powerful Cy

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ABSTRACT JANG, YUJIN. Synthesis of 1-Sulfonylcyclopropanols and Their Application in New Chemical Transformations As Powerful Cy ABSTRACT JANG, YUJIN. Synthesis of 1-Sulfonylcyclopropanols and Their Application in New Chemical Transformations as Powerful Cyclopropanone Equivalents. (Under the direction of Dr. Vincent Lindsay). Cyclopropanone, a notoriously strained cycloalkanone (Baeyer strain ca. 49 kcal/mol), is a promising three carbon building block in organic synthesis where all three C–C bonds are labile, and can be readily involved in ring-opening or ring-expansion. Despite its tremendous potential as a strained reagent, the difficulties associated with its handling and storage have precluded its widespread use in organic synthesis. For these reasons, a majority of cyclopropanone chemistry in the literature involves the use of equivalents such as hemiketals that can equilibrate to the parent ketone in situ via base-induced α-elimination. Although the classical hemiketals are suitable in some reactions, a number of potential transformations are still inaccessible, as harsh conditions are often required to generate cyclopropanone due to the poor leaving group ability of alkoxides and the immense strain generated in the process. In order to elevate the chemistry of cyclopropanones as common building blocks in synthesis, well-behaved cyclopropanone precursors are highly demanded. Here, we describe the efficient and convenient synthesis and application of unsubstituted 1-sulfonylcyclopropanols as powerful cyclopropanone equivalents. By tuning the electronic and steric nature of leaving group, a variety 1-sulfonylcyclopropanols were furnished, and the relative propensity of their equilibration to cyclopropanone was investigated in a novel pyrazole substitution reaction. With this well-behaved class of surrogates, we explored the C–C bond activation of this strained cycloalkanone in the presence of transition metals and organocatalysts. As a result, we discovered a new Ni-catalyzed [3+2] cycloaddition of cyclopropanone and internal alkynes, affording 2,3-disubstituted cyclopentenones with complete regiocontrol. Notably, the products formed are analogous to the ones obtained in the classical Pauson-Khand reaction, but with reverse regiocontrol. In addition, we studied the NHC-umpolung chemistry of cyclopropanone to achieve formal cycloaddition via C–C activation. We currently obtained several NHC-cyclopropanone adducts in moderate to good yield and further investigation of this novel class of compounds will be conducted in the future to understand their reactivity towards cycloaddition. Considering the importance of fluorine in the field of medicinal chemistry, life sciences and agrochemicals, the development of selective fluorination is urgent. We discovered selective formal β-fluorination of carboxylic derivatives via oxidative ring opening-fluorination of cyclopropanone equivalents. Here, we adopted pyrazole as a transient leaving group, which allows further functionalization of the carboxylic derivatives obtained. © Copyright 2021 by Yujin Jang All Rights Reserved Synthesis of 1-Sulfonylcyclopropanols and Their Application in New Chemical Transformations as Powerful Cyclopropanone Equivalents. by Yujin Jang A dissertation submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Chemistry Raleigh, North Carolina 2021 APPROVED BY: _______________________________ _______________________________ Dr. Vincent Lindsay Dr. Jonathan Lindsey Committee Chair _______________________________ _______________________________ Dr. Joshua Pierce Dr. Caroline Proulx DEDICATION I would like to dedicate this work to my parents. Without their lifelong support, I would never have reached this goal. ii BIOGRAPHY Yujin Jang was born and raised in Seoul, South Korea. She received her B.S. in Chemistry in 2010 and M.S. in Chemistry in 2012 from Kwangwoon University (South Korea), where she worked with Prof. Heung-bae Jeon, developing new synthetic methodologies for the synthesis of 1,2,3-triazoles and bistriazoles, and for the deoxygenation of sulfoxides. In 2012, she worked at Korea Institute of Ocean Science and Technology (KIOST) and conducted research on isolation of natural products and identification of their chemical structure as well as biological activities. From August 2014 until April 2016, she was a visiting scholar at the University of Kentucky, working with Prof. Kyung-Bo Kim on the development of a novel proteasome inhibitors with anti-cancer properties. She came to NC State University in August 2016 and joined the Lindsay lab, where she is working on the synthesis of 1-sulfonylcyclopropanols as cyclopropanone precursors and using them to design and develop new chemical transformations. iii ACKNOWLEDGMENTS I would like to express my deep gratitude to my advisor, Dr. Vincent Lindsay for his wonderful mentoring and advising me for the past five years, and for providing me a good research environment. I have learned a lot of things from him, and I would never have reached this goal without his support. I am also grateful to all my fellow group members for their help and sharing ideas for projects, and especially thanks to Roger Machín Rivera for helping me a lot and making it possible to work in a pleasant environment. I would like to thank Dr. Jonathan Lindsey, Dr. Joshua Pierce, Dr. Caroline Proulx and Dr. Emiel DenHartog for their willingness to serve on my committee and supporting my doctoral training. Lastly, I sincerely thank my family, especially my husband. iv TABLE OF CONTENTS LIST OF TABLES ....................................................................................................................... vii LIST OF FIGURES .................................................................................................................... viii LIST OF SCHEMES..................................................................................................................... ix LIST OF ABBREVIATIONS ........................................................................................................ x Chapter 1: General Introduction ............................................................................................... 1 1.1: Introduction to Strained Ring Systems ................................................................................... 1 1.2: Introduction to Cyclopropanone and its Derivatives .............................................................. 3 Chapter 2: Synthesis of 1-Sulfonylcyclopropanols and Kinetic Study of Their Equilibration to Cyclopropanone 2.1: Introduction to Cyclopropanone Equivalents ......................................................................... 6 2.1.1: Synthetic Approaches to Cyclopropanone Hemiketals ................................................. 7 2.2: Synthesis of 1-Sulfonylcyclopropanols .................................................................................. 9 2.3: Kinetic Study of Unsubstituted 1-Sulfonylcyclopropanols .................................................. 14 2.4: Conclusion ............................................................................................................................ 18 2.5: Experimental Details ............................................................................................................ 18 Chapter 3: Synthesis of 2,3-Disubstituted Cyclopentenones via Ni-Catalyzed C–C Activation of Cyclopropanone 3.1: Introduction to C–C bond Activation ................................................................................... 30 3.1.1: Transition Metal Catalyzed C–C Activation of Cyclobutanone .................................. 31 3.2: Investigation of Formal [3+2] Cycloaddition of Cyclopropanone ....................................... 32 3.3: Optimization of the Formation of Cyclopentenones ............................................................ 35 3.4: Scope of Accessible 2,3-Disubstituted Cyclopentenones..................................................... 41 3.5: Mechanistic Insights ............................................................................................................. 43 3.6: Conclusion ............................................................................................................................ 44 3.7: Experimental Details ............................................................................................................ 45 Chapter 4: NHC-Catalyzed Formal Cycloaddition of Cyclopropanone via Umpolung 4.1: Introduction to N-Heterocyclic Carbenes in Organocatalysis .............................................. 59 4.2: Introduction to Donor-Acceptor Cyclopropanes .................................................................. 60 4.2.1: Formal Cycloaddition of Donor-Acceptor Cyclopropanes ......................................... 61 4.3: Optimization of the Formation of NHC-Cyclopropanone Adducts ..................................... 64 4.4: Scope of Accessible NHC-Cyclopropanone Adducts .......................................................... 67 4.5: Evaluation of NHC Adducts toward Formal Cycloaddition ................................................ 68 4.6: Future Work .......................................................................................................................... 69 4.7: Conclusion ............................................................................................................................ 71 4.8: Experimental Details ..........................................................................................................
Load more

Recommended publications
  • Cyclopentane Synthesis
    Cyclopentane Synthesis Dan O’Malley Baran Group Meeting Cyclopentane Synthesis Group Meeting O'Malley 2/9/2005 This presentation is broken down into the following catagories. Some reactions either fit more than one Students of organic chemistry are taught a number of reactions for the synthesis of category or do not fit easily into any of them. Efforts have been made to place all such reactions in the cyclohexanes at a very early stage of their careers. Techniques for the creation of cyclopentanes, most appropriate category. however, are generally taught at a much later stage and are rarely given the same detailed treatment. This may be the result of the fact that there are no equivalents of reactions such as the Diels-Alder and I. General Information Robinson Annulation in terms of generality, extent of use, and historical importance. This may, in turn, II. Ionic Reactions be caused by the fact that the cyclopentane is an inherintly "umpoled" functionality, as illustrated below. III. Metal Mediated Reactions IV. Radical Reactions FG V. Pericyclic and Pseudo-pericyclic Reactions VI. Ring Expansion and Contraction Reactions I. General Information This situation is further exacerbated by the general lack of cheaply available cyclopentane compounds Baldwin's rules in the chiral pool; wheras a number of cyclohexane terpenes are readily available for elaboration, there Baldwin has divided ring closure reactions into those that are "favored" and those that are "disfavored". are no analogous cylcopentane natural products. Cyclopentanes are however, present in many Those that are disfavored are not always impossible, but are frequently much more difficult to effect.
    [Show full text]
  • Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy Petr Klan,́*,†,‡ Tomaś̌solomek,̌ †,‡ Christian G
    Review pubs.acs.org/CR Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy Petr Klan,́*,†,‡ Tomaś̌Solomek,̌ †,‡ Christian G. Bochet,§ Aurelień Blanc,∥ Richard Givens,⊥ Marina Rubina,⊥ Vladimir Popik,# Alexey Kostikov,# and Jakob Wirz∇ † Department of Chemistry, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic ‡ Research Centre for Toxic Compounds in the Environment, Faculty of Science, Masaryk University, Kamenice 3, 625 00 Brno, Czech Republic § Department of Chemistry, University of Fribourg, Chemin du Museé 9, CH-1700 Fribourg, Switzerland ∥ Institut de Chimie, University of Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France ⊥ Department of Chemistry, University of Kansas, 1251 Wescoe Hall Drive, 5010 Malott Hall, Lawrence, Kansas 66045, United States # Department of Chemistry, University of Georgia, Athens, Georgia 30602, United States ∇ Department of Chemistry, University of Basel, Klingelbergstrasse 80, CH-4056 Basel, Switzerland 7.3. Arylsulfonyl Group 160 7.4. Ketones: 1,5- and 1,6-Hydrogen Abstraction 160 7.5. Carbanion-Mediated Groups 160 7.6. Sisyl and Other Silicon-Based Groups 161 7.7. 2-Hydroxycinnamyl Groups 161 7.8. α-Keto Amides, α,β-Unsaturated Anilides, CONTENTS and Methyl(phenyl)thiocarbamic Acid 162 7.9. Thiochromone S,S-Dioxide 162 1. Introduction 119 7.10. 2-Pyrrolidino-1,4-Benzoquinone Group 162 2. Arylcarbonylmethyl Groups 121 7.11. Triazine and Arylmethyleneimino Groups 162 2.1. Phenacyl and Other Related Arylcarbonyl- 7.12. Xanthene and Pyronin Groups 163 methyl Groups 121 o 7.13. Retro-Cycloaddition Reactions 163 2.2. -Alkylphenacyl Groups 123 8. Sensitized Release 163 2.3. p-Hydroxyphenacyl Groups 125 p 8.1.
    [Show full text]
  • Screening Values for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals That Lack Established Occupational Exposure Limits
    PNNL-15640 Screening Values for Non-Carcinogenic Hanford Waste Tank Vapor Chemicals that Lack Established Occupational Exposure Limits TS Poet TJ Mast JL Huckaby February 2006 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor Battelle Memorial Institute, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or Battelle Memorial Institute. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. PACIFIC NORTHWEST NATIONAL LABORATORY operated by BATTELLE for the UNITED STATES DEPARTMENT OF ENERGY under Contract DE-AC05-76RL01830 Printed in the United States of America Available to DOE and DOE contractors from the Office of Scientific and Technical Information, P.O. Box 62, Oak Ridge, TN 37831-0062; ph: (865) 576-8401 fax: (865) 576-5728 email: [email protected] Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161 ph: (800) 553-6847 fax: (703) 605-6900 email: [email protected] online ordering: http://www.ntis.gov/ordering.htm This document was printed on recycled paper.
    [Show full text]
  • Carboxylic Acids and Their Derivatives
    8 CARBOXY A lmost all of the basic types of reactions now have been covered: addition, elimination, substitution, and rearrangement by polar, radical, and concerted mechanisms. Indeed, if you have been looking for similarities, you will have seen that most of the reactions discussed in the preceding three chapters are variations on basic types we have discussed earlier. Furthermore, most of the basic structural effects that determine chemical reactivity also have been covered in previous chapters: bond energies, steric hindrance, electronega- tivity, electron delocalization, hydrogen bonding, solvation, and conforma- tional influences. You might well ask what is left. The answer is, a great deal- but now we will be concerned mostly with putting concepts together, moving from the simple to the complex. For example, in this chapter we will be trying to under- stand the ways that carboxylic acids, which possess the -c' functional \ group, are similar to and different from alcohols, which have the OH group, and aldehydes and ketones, which have C=O bonds. Subsequently we will look at acids that also possess OH or NH, sub- stituent groups (or both) and develop a rationale for the behavior of these combinations in terms of effects we already have discussed. Insofar as pos- sible, you should try to do this yourself whenever you encounter a substance with a new set of combinations of functional groups on its molecules. You often will be in error (as many experts will be), because even if you take Carboxylic Acids and Their Derivatives 789 account of all of the structural effects, as well as the possible reactions or inter- actions, the overall result of these frequently is very difficult to judge in advance.
    [Show full text]
  • Aldehydes, Ketones and Carboxylic Acids
    1212Unit Objectives AldehydesAldehydesAldehydesAldehydes,,,,,, KKKKKKeeeeeetonestonestonestonestonestones After studying this Unit, you will be able to andandandandandand CarboxylicCarboxylicCarboxylicCarboxylicCarboxylicCarboxylic • write the common and IUPAC names of aldehydes, ketones and carboxylic acids; AAAAAAcidscidscidscidscidscids • write the structures of the compounds containing functional groups namely carbonyl and carboxyl groups; Carbonyl compounds are of utmost importance to organic chemistry. They are constituents of fabrics, flavourings, plastics • describe the important methods and drugs. of preparation and reactions of these classes of compounds; In the previous Unit, you have studied organic • correlate physical properties and compounds with functional groups containing carbon- chemical reactions of aldehydes, oxygen single bond. In this Unit, we will study about the ketones and carboxylic acids, organic compounds containing carbon-oxygen double with their structures; bond (>C=O) called carbonyl group, which is one of the • explain the mechanism of a few most important functional groups in organic chemistry. selected reactions of aldehydes and ketones; In aldehydes, the carbonyl group is bonded to a carbon and hydrogen while in the ketones, it is bonded • understand various factors to two carbon atoms. The carbonyl compounds in which affecting the acidity of carboxylic carbon of carbonyl group is bonded to carbon or acids and their reactions; hydrogen and oxygen of hydroxyl moiety (-OH) are • describe the uses of aldehydes, known as carboxylic acids, while in compounds where ketones and carboxylic acids. carbon is attached to carbon or hydrogen and nitrogen of -NH2 moiety or to halogens are called amides and acyl halides respectively. Esters and anhydrides are derivatives of carboxylic acids. The general formulas of these classes of compounds are given below: 2021–22 Aldehydes, ketones and carboxylic acids are widespread in plants and animal kingdom.
    [Show full text]
  • Nucleophilic Addition to the Carbonyl Group 6
    Nucleophilic addition to the carbonyl group 6 Connections Building on Arriving at Looking forward to • Functional groups, especially the C=O • How and why the C=O group reacts • Additions of organometallic group ch2 with nucleophiles reagents ch9 • Identifying the functional groups in a • Explaining the reactivity of the C=O • Substitution reactions of the C=O molecule spectroscopically ch3 group using molecular orbitals and curly group’s oxygen atom ch11 • How molecular orbitals explain arrows • How the C=O group in derivatives of molecular shapes and functional • What sorts of molecules can be made by carboxylic acids promotes substitution groups ch4 reactions of C=O groups reactions ch10 • How, and why, molecules react together • How acid or base catalysts improve the • C=O groups with an adjacent double and using curly arrows to describe reactivity of the C=O group bond ch22 reactions ch5 Molecular orbitals explain the reactivity of the carbonyl group We are now going to leave to one side most of the reactions you met in the last chapter—we will come back to them all again later in the book. In this chapter we are going to concentrate on just one of them—probably the simplest of all organic reactions—the addition of a nucleo- phile to a carbonyl group. The carbonyl group, as found in aldehydes, ketones, and many other compounds, is without doubt the most important functional group in organic chemis- try, and that is another reason why we have chosen it as our fi rst topic for more detailed study. You met nucleophilic addition to a carbonyl group on pp.
    [Show full text]
  • Photochemical Reactions of Cyclohexanone: Mechanisms and Dynamics Published As Part of the Journal of Physical Chemistry a Virtual Special Issue “Mark S
    Article pubs.acs.org/JPCA Photochemical Reactions of Cyclohexanone: Mechanisms and Dynamics Published as part of The Journal of Physical Chemistry A virtual special issue “Mark S. Gordon Festschrift”. † ‡ † ‡ Dorit Shemesh, Sergey A. Nizkorodov, and R. Benny Gerber*, , † Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel ‡ Department of Chemistry, University of California, Irvine, California 92697, United States *S Supporting Information ABSTRACT: Photochemistry of carbonyl compounds is of major importance in atmospheric and organic chemistry. The photochemistry of cyclohexanone is studied here using on-the- fly molecular dynamics simulations on a semiempirical multi- reference configuration interaction potential-energy surface to predict the distribution of photoproducts and time scales for their formation. Rich photochemistry is predicted to occur on a picosecond time scale following the photoexcitation of cyclo- hexanone to the first singlet excited state. The main findings include: (1) Reaction channels found experimentally are confirmed by the theoretical simulations, and a new reaction channel is predicted. (2) The majority (87%) of the reactive trajectories start with a ring opening via C−Cα bond cleavage, supporting observations of previous studies. (3) Mechanistic details, time scales, and yields are predicted for all reaction channels. These benchmark results shed light on the photochemistry of isolated carbonyl compounds in the atmosphere and can be extended in the future to photochemistry of more complex atmospherically relevant carbonyl compounds in both gaseous and condensed-phase environments. I. INTRODUCTION representative examples are given), acetaldehyde,8 propanal,9 10 11 The photochemistry of carbonyl compounds is an important butanal and its derivatives, heptanal, and other small − 12 topic in organic and atmospheric chemistry.1 3 Atmospheric aldehydes.
    [Show full text]
  • Calculations 273 Absolute Asymmetric Synthesis 634, 635 Absolute
    1317 Index A activation enthalpy 23, 39, 188, 195–196, 204, 205, 206, aaptosine 358, 359 217, 339, 341, 345, 370, 393, 398, 411, 412, 443, 444, ab initio Hartree–Fock (HF) calculations 273 452, 453, 462, 465, 500, 697, 728 absolute asymmetric synthesis 634, 635 activation entropy 39, 188, 190, 192–196, 198, 369, 500, absolute electronegativity 37 689, 695, 872 absolute hardness 37–39, 839 activation entropy and reaction mechanism absolute softness 37 – Cope rearrangement 195 absorbance 616 – gas phase – – homolysis and radical combination 192–193 absorption complex 624, 667 – – isomerizations 193–194 absorption on crystalline quartz 44 – neighboring group directing effects 197 acetaldehyde 15, 18, 60, 66, 70, 80, 82, 86, 145, 146, 147, – retro-carbonyl-ene reaction 195–197 195, 197, 223, 514, 551, 619, 683, 686, 697, 732, 797, activation parameters 819, 855, 920, 921, 1168 – Curtin–Hammett principle 190–192 acetamide 62, 66, 82, 89, 619 – temperature effect, two parallel reactions 190 acetic acid 12, 13, 49, 60, 87, 89, 151, 373, 503, 619, 650, acyclic ,-and,-enones 60, 642 699, 800, 808, 900, 1030, 1032–1034, 1050 acyclic alkylaminocarbene 439 acetic anhydride 12, 61, 216, 619, 802, 1033 acyclic diene 55, 468, 633, 1126 acetone 15, 25, 35, 36, 60, 70, 80, 85, 86, 88, 90, 122, acyclic 1,3-dienes 55, 697, 698 143, 146–148, 153, 203, 210, 213, 224, 226, 229–232, acyclic dithiosilylene 448 373, 374, 382, 383, 412, 413, 435, 619, 622, 623, 628, acyclic peroxides 729 633, 637, 638, 641, 656, 662, 669, 671, 682, 685, 686, (1,2)-acyloxy shifts
    [Show full text]
  • Study on the Fate of Pharmaceuticals in Aqueous Media: Synthesis, Characterization and Detection of Biotic and Abiotic Transform
    Study on the fate of pharmaceuticals in aqueous media : synthesis, characterization and detection of biotic and abiotic transformation products using electrochemical advanced oxidation processes and bioconversions Hugo Olvera Vargas To cite this version: Hugo Olvera Vargas. Study on the fate of pharmaceuticals in aqueous media : synthesis, character- ization and detection of biotic and abiotic transformation products using electrochemical advanced oxidation processes and bioconversions. Biodiversity and Ecology. Université Paris-Est; Erasmus Mundus EteCoS3, 2014. English. NNT : 2014PEST1179. tel-01207532 HAL Id: tel-01207532 https://tel.archives-ouvertes.fr/tel-01207532 Submitted on 1 Oct 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Joint PhD degree in Environmental Technology Docteur de l’Université Paris-Est Spécialité : Sciences et Techniques de l’Environnement Dottore di Ricerca in Tecnologie Ambientali Degree of Doctor in Environmental Technology Thèse – Tesi di Dottorato – PhD thesis Hugo Olvera-Vargas Study on the Fate of Pharmaceuticals in Aqueous Media: Synthesis, Characterization and Detection of Biotic and Abiotic Transformation Products using Electrochemical Advanced Oxidation Processes and Bioconversions To be defended on December the 17th, 2014 In front of the PhD committee Prof. Marco Panizza Reviewer Prof.
    [Show full text]
  • Molecular Modeling Experiment
    (004:141) Experiment #11 MOLECULAR MODELING: AROMATIC RESONANCE EFFECTS IN CYCLIC KETONES Goal: In this experim ent, you will us e computational chemistry to probe the effects of aromaticity upon bond strengths and lengths. The vibrational spectral frequencies for a variety of cyclic ketones will b e predicted using m olecular orbital methods, and the trends in bond length and C=O stretching frequency will be com pared to expectations based on resonance theory and aromaticity models. If you wish you may work in groups of two or three, and share the results of your computations. Discuss th e results am ongst yourselves, but each person must write up and submit his or her own report. For the calculations, use the PC SPART AN ‘02 com puter program (Wavefunction Inc.) on PCs in the Chemistry Department (locations will be announced). You will draw and calculate properties of each of the molecules shown below: O O O O O O 1 (004:141) Experiment #11 Background Principles of Resonance Kekulé structural formulas are essential tools for understanding organic chem istry. However, the structures of som e compounds and ions cannot be represented by a single formula. For example, sulfur dioxide (SO2) and nitric acid (HNO3) may each be described by two equivalent formulas (equations 1 & 2). For clarity the two am biguous bonds to oxygen are given different colors in these formulas. If only one formula for sulfur dioxide were correct and accurate, then the double bond to oxygen would be shorter and stronger than the single bond. Since experim ental evidence indicates that this molecule is bent (bond angle 120°) and has equal lengths of sulfur-oxygen bonds (1.432 Å), a single formula is inadequate, and the actual structure resembles an average of the two form ulas.
    [Show full text]
  • A Study Op the Kinetics Op Hydrolysis Op
    A STUDY OP THE KINETICS OP HYDROLYSIS OP CYCLOALKANONE DIALKYL KETALS DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By WALTER THOMAS REICHLE, B.S. The Ohio State University 1958 Approved by: Adviser Department of Chemistry ACKNOWLEDGMENTS I I wish to express my deep apprecia­ tion for the guidance, help, and advice which I have received from Dr. Harold Shechter during the course of this investi­ gation. I am grateful to the General Electric Company and the National Science Foundation for fellowship funds. I also wish to thank the taxpayers of the State of Ohio and those of the United States of America for their liberal, indirect aid. ii DEDICATED To H.S.S. and My Wife, for the many lonely hours. iii TABLE OP CONTENTS Page I, INTRODUCTION ................................ 1 II. THE MECHANISMS OP THE HYDROLYSIS OF ACETALS AND K E T A L S ..................... 4 III. DISCUSSION OF RESULTS OF THE PRESENT INVESTIGATION ................. 19 The Kinetics of Hydrolysis of Homologous Cyclanone Dimethyl K e t a l s .......... 19 The Effect of the Alcohol Groups on the Rates of Hydrolysis of Cyciobutanone, Cyclopentanone, and Cyclohexanone Dialkyl Ketals ........ 33 The Effect of Alkyl Groups on the Rates of Hydrolysis of Methyl Ring-substituted Cyciobutanone, Cyclopentanone, and Cyclohexanone Dimethyl K e t a l s ......................... 43 Free Energy Relationships of Reactions of Cyclic Molecules .......... 58 IV, EXPERIMENTAL Constant Temperature B a t h ............... 6? Temperature Measurements ................. 68 Miscellaneous ............................ 69 Kinetic Procedure ....................... 71 Calculations .............................. 75 Special Calculations for the Hydrolysis of the Ten-membered Ketal .
    [Show full text]
  • 3-Hydroxybutanal
    Class 12 Chemistry Aldehydes, Ketones And Carboxylic Acids Ncert Video Solutions - Only On Doubtnut Download Doubtnut Now Exercise 12.1 Write the structures of the following compounds. (i) α-Methoxypropionaldehyde (ii) 3-Hydroxybutanal (iii) 2-Hydroxycyclopentane carbaldehyde (iv) 4-Oxopentanal (v) Di-sec. butyl ketone (vi) 4-Fluoroacetophenone Watch Video Solution On Doubtnut App Exercise 12.2 Write the structures of products of the following reactions, Watch Video Solution On Doubtnut App Exercise 12.3 Arrange the following compounds in increasing order of their boiling points. CH3CHO, CH3CH2OH, CH3OCH3, CH3CH2CH3 Watch Video Solution On Doubtnut App Exercise 12.4 Arrange the following compounds in increasing order of their reactivity in nucleophilic addition reactions. (i) Ethanal, Propanal, Propanone, Butanone. (ii) Benzaldehyde, p-Tolualdehyde, p-Nitrobenzaldehyde, Acetophenone. Hint: Consider steric effect and electronic effect. Watch Video Solution On Doubtnut App Exercise 12.5 Predict the products of the following reactions: Watch Video Solution On Doubtnut App Exercise 12.6 Give the IUPAC names of the following compounds: (i) Ph CH2CH2COOH (ii) (CH3)2C = CHOOH Watch Video Solution On Doubtnut App Exercise 12.7 Show how each of the following compounds can be converted to benzoic acid. (i) Ethylbenzene (ii) Acetophenone (iii) Bromobenzene (iv) Phenylethene (Styrene) Watch Video Solution On Doubtnut App Exercise 12.9 What is meant by the following terms ? Give an example of the reaction in each case. (i) Cyanohydrin (ii) Acetal (iii) Semicarbazone (iv) Aldol (v) Hemiacetal (vi) Oxime (vii) Ketal (vii) Imine (ix) 2,4-DNP-derivative (x) Schiffs base Watch Video Solution On Doubtnut App Exercise 12.10 Name the following compounds according to the IUPAC system of nomenclature: i.
    [Show full text]