DOCSLIB.ORG

The Nonclassical Norbornyl Cation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Nonclassical Norbornyl Cation This dissertation has been microfilmed exactly as received 66-15,112 MARSHALL, James Lawrence, 1940- THE NONCLASSICAL NORBORNYL CATION. The Ohio State University, Ph.D., 1966 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan THE NONCLASSICAL NORBORNYL CATION DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By James Lawrence Marshall*, B .S. sic*###* The Ohio State University 1966 Approved by p / J- A - Adviser Department of Chemistry ACKNOWLEDGMENTS The author is indebted to the National Science Foundation and the Petroleum Research Foundation for partial support of this research. ii VITA James Lawrence Marshall, the son of Madison L. and Irene V. Marshall,, was bora in Denton, Texas, on May 19, 1940. After gaining his elementary education in this city, his family moved to Decatur,. Alabama, in June 1952» where he attended Decatur High School. In September 1958, he entered Davidson College, Davidson, North Carolina, on a Proctor and Gamble Scholarship. After two years he transferred to Indiana University, Blooming­ ton, Indiana, where-he received his B.S. in chemistry in June 1962. The following September he entered the Graduate School of The Ohio State University. In March 1963 > he married Julia Clark Bechtel of Niles, Michigan. The following appointments were held: 1962-1963 N.S.F. Cooperative Fellowship 1964-1965 " '* " 1965-1966 " " " I 963.-I964 Petroleum Research Foundation Fellowship In June 1966, he received his Ph.D. in organic chemistry from The Ohio State University. iii CONTENTS Page ACKNOWLEDGMENTS............................................................................................... i i VITA......................................................................................................................... i i i TABLES ............................................................................................................... ^ ILLUSTRATIONS ................................................................................................... x i INTRODUCTION ................................................................................................... 1 PART I . THE 2-NORBORNYL CATION.......................................................... 8 1* The problem ................................... 8 Known classical norbornyl systems ........ 15 The transition s ta te .............................................................. 19 2. Approach to the problem ........................................ 23 3 . R e s u l t s .......................................................................................... 27 PART I I . THE 7-NQRBORNENYL C A T IO N .................................................. 65 1 . The p r o b l e m ................................................................................. 65 2. Approach to the problem ...................................................... 69 3 . R e s u l t s .......................................................................................... 70 EXPERIMENTAL................................................................................................... 103 R e a g e n ts ................................................................................................... 103 5 jL5 -Dimethoxy-l ,2 »3*4-tetrachloro- cy clo p en tad ien e C51) 104 7 >7-D im ethoxy-l>2, 3 ,4-tetrachloro- bicyclo[2.2.1]hept-2-ene ($2) 104 7j7-Dimethoxybicyclo[2.2.1]heptene (jQ) ....................... 105 iv CONTENTS (C ontinued) - . Page Hydroboration of 7>7-dimethoxybicyclo - [ 2 . 2 .1]heptene (52.) ............................... 105 7, 7-Diniethoxybicyclo[ 2 . 2 .1 ]heptane-exo- 2 >3-epoxide ( 67 ) .................................................................... 106 7»7-Dimethoxybicyclo[2.2.1]heptan-exo-2-ol (54) . 107 7»7-Dimethoxybicyclo[2.2.1]heptan-2-one ( 66 ) .... 108 2 ,4-Dinitrophenylhydra zone of 7» 7-dimethoxy- b ic y c lo [ 2 . 2 .1 ]h e p ta n - 2-one ............................................. 108 7>7-Eimethoxybicyclo[2.2.1]heptan-endo-2-ol (55) . 109 Oxidation of 7*7-dimethoxybicyclo[2.2.1]- heptan-endo- 2- o l ( 55 ) ...................... 110 Reduction of 7>7-dimethoxybicyclo[2.2.1]- h e p ta n - 2-one ( 66 ) with sodium-ethanol ...... 110 Reduction of 7i7-d:methoxybicyclo[2.2.1]heptan- 2-one ( 6 6 ) with lithium aluminum hydride .... 110 Reduction of 7x7-diroe'thoxybicyclo[2.2.1]heptane- exo -2 ,.3-epoxide with lithium-ethylamine .. I l l exo-2-Acetoxy-7,7-diraethoxybicyclo[2.2.13- heptane ( 62 ) ................................................................ I l l endo-2-Acetoxy-7>7-dimethoxybicyclo[2. 2 * 1 ]- heptane ( 63 ) ............................................................ 112 7 *7-Dimethoxybicyclo[2.2,l]heptan-exo-2-ol 2-toluene sulfonate (6 4 ) ...................... 112 7 >7-Dimethoxybicyclo[ 2 . 2 .l]heptan-endo- 2- o l 2 -toluenesulfonate ( 65 ) ...................................................... 113 exo-2-Hydroxybicyclo[2.2. 1 ]heptan-7-one ( 5 6 ) .... 113 exo-2-Acetoxybicyclo \ 2 . 2 .llheotan-7-one ( 60 ) .... 114 exo-2-Acetoxybicyclo[2.2.l]heptan-7-one ( 60 ) via the hydrolysis of exo- 2- a c e toxy -7 »7- dimethoxybicyclo[ 2 . 2 . 1 ]heptane ( 62 ) ........................... 114 v CONTENTS (Continued) Page exo-2-Hydroxybicyclo[2.2.1]heptan-7-one jo-toluenesulfonate (£8 ) . .................................................... 115 endo-2-Hydroxybicyclo [2 .2.llheptan-7-one (57) .... 115 endo-2-Acetoxybicyclo[2.2.1]heptan-7-one ( 6 l ) .... 115 endo-2-Hydroxybicyelof 2.2. 1 ]hepta n-7-one £-toluenesulfonate (£2 ) ..................................................... I l 6 Reduction of exo-2-acetoxybicyclof2.2.11- h ep tan - 7-one ( 6 o) with lithium aluminum h y d rid e ................................................................... 116 7-Ketobicyclo[2.2.1]heptene ( 7 5 ) ................................ 117 7>7-exo-2-Trimethoxybicyclo[2.2.1]heptene ( 80) . 117 exo-2-Methoxybicyclor 2 . 2 . 1 Iheptan-7-one ( 78) . ... 118 exo-2-syn-7-Bicyclof2.2.1Iheptanediol ( 6 8 ) .................. 118 exo-2-anti-7-Bicyclor2.2.11heptanediol (10b) .... 119 7-t-Butoxybicyclo[2.2.1]heptadiene .................................... 119 7-Acetoxybicyclo[2.2.1]heptadiene ........................... 120 a n ti- 7-Rydroxybicyclor 2 . 2 .llheptene tetra- hydropyranyl e th e r ............................................................... 121 exo~2-anti-7-Bicyclor2.2.1Iheptanediol (106) . 121 syn-7-Hydroxybicyclor2.2.1lheptan-2-one (107) .... 122 syn-7-Hydroxybicyclof2.2.1]heptan-2-one jo-toluene- sulfonate (103) via Jones oxidation of exo-2- syn-7-bicyclor2.2.11heptanediol ( 68 ) ....................... 123 syn-7-Hydroxybicyclof 2.2.llheptan-2-one £-toluene- sulfonate (103) via chromic acid-water oxi­ dation of exo- 2-sy n - 7-b ic y c lo r 2 . 2 . 11- heptanediol ( 68 ) ................................................................... exo-2-syn-7-Bicyclor 2 . 2 .l]heptanediol-di £-toluenesulfonate ( 108) ................................ 12if vi CONTENTS (Continued) Page syn-7-Hyd roxybicyclo[2.2.1]h epta n-2-one ^-toluenesulfonate (103) via solvolysis o f ex o - 2- syn- 7-b ic y c lo r 2 . 2 .llheotane- diol di-£-toluenesulfonate ( 108) ........................... 125 anti-7-Hydroxybicyclo[2.2.1]heptan-2-one ( 110) .... 126 anti-7-Hydroxybicyclor 2 . 2 .llheptan-2-one £-toluenesulfonate (104) ....................................................... 126 exo-2-anti-7-Bicyclo[2.2.l]heptanediol di-£-toluenesulfonate (ill) . ......................................... 127 an ti-7-H.yd roxybicyc lo [ 2.2 .l]heptan-2-one £-toluenesulfonate (104) via solvolysis o f exo- 2- a n t i - 7- b ic y c lo [ 2 . 2 .l]heptane- diol di-£-toluenesulfonate (ill) ..................................... 127 s,yn-7-Acetox,ybicyclo f 2.2 .llheptan-2-one (113.) .... 129 anti-7-Acetoxybicyclo[2.2.1]heptan-2-one (114) .... 130 KINETICS................................................................................................................. 131 Reagents . .................................................................... ...... 131 Kinetics procedure ............................................................................. 132 Acetolysis product analysis of exo-2-hydroxy- b ic y c lo [ 2 . 2 .l] h e p ta n - 7~one £-toluene- sulfonate (38) ........ ......................................... 134 Acetolysis product analysis of endo-2-hydroxy- b ic y c lo [ 2 . 2 .l] h e p ta n - 7-one £-toluene- sulfonate (. 59 ) .......................... 136 Acetolysis product analysis of 7» 7-diroethoxy- b ic y c lo [ 2 . 2 ,l]heptan-exo- 2-ol £-toluene- sulfonate (64) ............................... 136 Dioxane-water solvolysis product analysis of 7 * 7-dimethoxybicyclo[ 2 .2 »l]heptan-exo- 2-ol £-toluenesulfonate (64) ......................................... 137 Acetolysis product analysis of ? ,7-dimethoxy- b ic y c lo [ 2 . 2 .1 ]heptan-endo- 2- o l £_ toluenesulfonate ( 65 ) 137 vii CONTENTS (Continued.) Page Acetolysis product analysis of anti-7-h.ydroxy- bicyclo[2.2.1]heptan-2-one £-toluene- sulfonate (104) ................................................................... 138 Acetolysis product analysis of syn-7-hydroxy- bicyclo[2.2.1]heptan-2-one £-toluene- sulfonate (103) ............................... 13.8 Partial acetolysis of anti-7-h.ydroxybicyclo- [ 2 .2 »l]heptan- 2-one £-toluenesulfonate (104) in acetic acid- 0-d ...................... 140 APPENDIXES.......................................................................................................
Load more

Recommended publications
  • Alcohol Oxidation
    Alcohol oxidation Alcohol oxidation is an important organic reaction. Primary alcohols (R-CH2-OH) can be oxidized either Mechanism of oxidation of primary alcohols to carboxylic acids via aldehydes and The indirect oxidation of aldehyde hydrates primary alcohols to carboxylic acids normally proceeds via the corresponding aldehyde, which is transformed via an aldehyde hydrate (R- CH(OH)2) by reaction with water. The oxidation of a primary alcohol at the aldehyde level is possible by performing the reaction in absence of water, so that no aldehyde hydrate can be formed. Contents Oxidation to aldehydes Oxidation to ketones Oxidation to carboxylic acids Diol oxidation References Oxidation to aldehydes Oxidation of alcohols to aldehydes is partial oxidation; aldehydes are further oxidized to carboxylic acids. Conditions required for making aldehydes are heat and distillation. In aldehyde formation, the temperature of the reaction should be kept above the boiling point of the aldehyde and below the boiling point of the alcohol. Reagents useful for the transformation of primary alcohols to aldehydes are normally also suitable for the oxidation of secondary alcohols to ketones. These include: Oxidation of alcohols to aldehydes and ketones Chromium-based reagents, such as Collins reagent (CrO3·Py2), PDC or PCC. Sulfonium species known as "activated DMSO" which can result from reaction of DMSO with electrophiles, such as oxalyl chloride (Swern oxidation), a carbodiimide (Pfitzner-Moffatt oxidation) or the complex SO3·Py (Parikh-Doering oxidation). Hypervalent iodine compounds, such as Dess-Martin periodinane or 2-Iodoxybenzoic acid. Catalytic TPAP in presence of excess of NMO (Ley oxidation). Catalytic TEMPO in presence of excess bleach (NaOCl) (Oxoammonium-catalyzed oxidation).
    [Show full text]
  • Chromic Acid Oxidation of Hydrocarbons at The
    CHROMIC ACID OXIDATION OF HYDROCARBONS AT THE BENZYLIC POSITION USING THE JONES REAGENT AND C-13 NMR STUDIES OF GEM-DIMETHYL­ INDANS AND -INDANONES By Radhika Rangarajan Ii Bachelor of Science Annamalai University Annamalai Nagar, India 1979 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY December, 1984 1hes\s )ti84 D ~ \°' U,£!-­ c.o p, ~ BENZYLIC POSITION USING THE JONES REAGENT AND C-13 NMR STUDY OF GEM-DIMTHYL­ INDANS AND -INDANONES Thesis Approved: (] . Dean of the Graduate College ii 1218538 •t ACKNOWLEDGMENTS I wish to begin with expressing my whole-hearted gratitude to Dr. E. J. Eisenbraun for his care and guidance during the course of this research. My committee members Dr. R. A. Bunce, Dr. E. M. Holt and Dr. E. C. Nelson have been very helpful in carefully evaluating this work. I appreciate all their help. I would like to thank Dr. T. Rangarajan, Dr. Pourahmady, Mr. Stan Sigle and Mr. Norm Perreira, who played an important role in this investigation. I acknowledge the financial support provided by the Oklahoma State University, Department of Chemistry, Department of Energy and Dow Chemical Company during my graduate tenure. I extend my deepest appreciation to my parents, Rangarajan and Shantha Rangarajan, without whose encouragement this study would not have been possible. A special thanks is due to Mrs. Lisa Thompson for typing my manuscript. iii TABLE OF CONTENTS Chapter Page I. INTRODUCTION AND HISTORICAL. 1 II. RESULTS AND DISCUSSION •• . 15 General •••••• . 15 Oxidation of Hydrocarbons •••••••• 19 Estimation of Solvent Consumption.
    [Show full text]
  • Still More Carbonyl Chemistry
    Lecture 17 Still More Carbonyl Chemistry March 26, 2019 Chemistry 328N Second Midterm Exam ⚫ When: Tomorrow, Wednesday, 3/27 ⚫ When: 7-9 PM (please do not be late) ⚫ Where: Painter 3.02!!! ⚫ What: Covers through last Thursday’s lecture ⚫ Remember: Homework problems!! ⚫ Please…bring pencils and an eraser no calculator and no phones …….Do a good job!!! Chemistry 328N Early Exam ⚫ Authorized students with exam conflict ⚫ When: 5-7 PM Tomorrow, 3/27 ⚫ Where: ETC 2.136 ⚫ Pencil and eraser no calculator and no phone ⚫ You must stay in the exam room until 7 PM Chemistry 328N Chromic Acid Oxidations Chemistry 328N Chemistry 328N Erin Brokovich ⚫ Hexavalent chromium compounds (including chromium trioxide, chromic acids, chromates, chlorochromates) are toxic and carcinogenic. Chemistry 328N Oxidation at Benzylic Positions O H H C OH H2SO4, K2CrO4 Heat KMnO4 in Base also works Chemistry 328N Selective Chromate Oxidations ⚫ Chromic acid and heat Oxidizes benzylic positions bearing at least one hydrogen to acids ⚫ Jones Reagent (H2CrO4 in acetone) takes primary alcohols to acids and secondary alcohols to ketones…The acetone keeps the reaction cool. Jones oxidation does not oxidize benzylic positions even with a hydrogen. ⚫ PCC (pyridinium chlorochromate) is weaker yet, it only oxidizes primary alcohols to aldehydes (!) and seconday alcohols to ketones. Chemistry 328N The Jones Oxidation Examples H2 SO4 H2 CrO4, Acetone OH OH O O O C C H2SO4 H OH H 2CrO4,Acetone H3C H3C OH O H2 CrO4, Acetone Chemistry 328N PCC Oxidations C5H5N + HCl + CrO3 → [C5H5NH][CrO3Cl]
    [Show full text]
  • Alcohol Oxidations – Beyond Labz Virtual Chemlab Activity
    Alcohol Oxidations – Beyond Labz Virtual ChemLab Activity Purpose: In this virtual experiment, you will be performing two oxidation reactions of benzyl alcohol, a primary alcohol. Primary alcohols can be oxidized to aldehydes or carboxylic acids, depending on the reagents used. You will be setting up oxidation reactions using chromic acid (H2CrO4) and pyridinium chlorochromate (PCC), and comparing the products of the two reactions. You will be monitoring the reactions using thin-layer chromatography (TLC) and analyzing IR and NMR spectra of the reactants and products. O further O OH oxidation oxidation H OH benzyl alcohol benzaldehyde benzoic acid Figure 1. Oxidation reactions of benzyl alcohol Introduction: Primary alcohols can be oxidized to aldehydes or carboxylic acids, depending on the reagents used. For many years, chromium reagents were commonly used for alcohol oxidations. Because of the toxicity of chromium-based reagents, many safer oxidizing agents have been developed and are more commonly used. As this lab is virtual, we can safely explore the reactivity trends for the older, chromium-based reagents. The two reaction conditions we will be exploring in this virtual experiment are: • Jones oxidation: This reaction uses chromic acid (H2CrO4) as the oxidizing agent. Chromic acid can be formed by dissolving sodium dichromate (Na2Cr2O7) or chromium trioxide (CrO3) in aqueous sulfuric acid (H2SO4). • PCC oxidation: This reaction uses pyridinium chlorochromate (PCC) in an anhydrous solvent, typically dichloromethane (CH2Cl2). The virtual lab does not give us CH2Cl2 as an option for a solvent, so we will substitute diethyl ether (CH3CH2OCH2CH3, or Et2O). Once your two virtual experiments are complete, you will decide which set of conditions oxidizes primary alcohols to aldehydes, and which oxidizes primary alcohols to carboxylic acids.
    [Show full text]
  • 17. Oxidation and Reduction Reactions 18
    (11,12/94)(4,5/97)(02,3/07)(01/08) Neuman Chapter 17 Chapter 17 Oxidation and Reduction from Organic Chemistry by Robert C. Neuman, Jr. Professor of Chemistry, emeritus University of California, Riverside [email protected] <http://web.chem.ucsb.edu/~neuman/orgchembyneuman/> Chapter Outline of the Book ************************************************************************************** I. Foundations 1. Organic Molecules and Chemical Bonding 2. Alkanes and Cycloalkanes 3. Haloalkanes, Alcohols, Ethers, and Amines 4. Stereochemistry 5. Organic Spectrometry II. Reactions, Mechanisms, Multiple Bonds 6. Organic Reactions *(Not yet Posted) 7. Reactions of Haloalkanes, Alcohols, and Amines. Nucleophilic Substitution 8. Alkenes and Alkynes 9. Formation of Alkenes and Alkynes. Elimination Reactions 10. Alkenes and Alkynes. Addition Reactions 11. Free Radical Addition and Substitution Reactions III. Conjugation, Electronic Effects, Carbonyl Groups 12. Conjugated and Aromatic Molecules 13. Carbonyl Compounds. Ketones, Aldehydes, and Carboxylic Acids 14. Substituent Effects 15. Carbonyl Compounds. Esters, Amides, and Related Molecules IV. Carbonyl and Pericyclic Reactions and Mechanisms 16. Carbonyl Compounds. Addition and Substitution Reactions 17. Oxidation and Reduction Reactions 18. Reactions of Enolate Ions and Enols 19. Cyclization and Pericyclic Reactions *(Not yet Posted) V. Bioorganic Compounds 20. Carbohydrates 21. Lipids 22. Peptides, Proteins, and α−Amino Acids 23. Nucleic Acids **************************************************************************************
    [Show full text]
  • The Oxidation of Terminal Olefins to Methyl Ketones by Jones Reagent Is Catalyzed, by Mercury(Il)
    [Reprinted from the .Journalof Organic Chemistry'.{0. i]r77 ( 1975).l Copvright 19?5by the American Chemical Societvand reprinted bv permissionof the copyright owner. The Oxidation of Terminal Olefins to Methyl Ketones by Jones Reagent Is Catalyzed,by Mercury(Il)t Harold R. Rogers, Joseph X. McDermott,2 and George M. Whitesides* Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 ReceiuedJune 11. 1975 The oxidation of terminal olefins by Jones reagent in the presence of a catalytic quantity of mercury(II) affords good yields (>lO"t") of the corresponding methyl ketones. Similar oxidations of 1,2-disubstituted olefins gives fair (20-70%) yields; in the caseof unsymmetrically substituted olefins, mixtures of ketones are produced. The Wacker process for oxidation of olefins to ketones products) different from those of the Wacker oxidation. has three mechanistically distinct parts:3 first, activation of Mercury(Il) is an obvious candidate for the catalyst for the olefinic double bond toward nucleophilic attack by new oxidation reactions: it resembles palladium(Il) in its coordination with Pd(II) and addition of a hydroxide moi- ability to activate olefins for nucleophilic attack,a but dif- ety to this electrophilic double bond; second, conversion of fers in that decomposition of the oxymercuration products the resulting 2-hydroxyethylpalladium(Il) compound to normally generates cations by loss of mercury(0) rather ketone and a (formally) Pd(O) atom by a series of palladi- than olefins by loss of mercury hydride.s Unfortunately, um(II) hydride addition-eliminations involving vinylic al- neither we nor others6 have been able to discover a satisfac- cohol intermediates; third, reoxidation of the palladium(0) tory solution to the principal problem in developing a mer- to palladium(Il) by copper(Il).
    [Show full text]
  • Design, Synthesis and Structure-Activity
    CARLA LOPES VARELA DESIGN, SYNTHESIS AND STRUCTURE-ACTIVITY RELATIONSHIPS STUDIES ON STEROIDAL AROMATASE AND 5α-REDUCTASE INHIBITORS AS ANTI-TUMORS Faculty of Pharmacy University of Coimbra 2013 CARLA LOPES VARELA DESIGN, SÍNTESE E ESTUDOS DE RELAÇÃO ESTRUTURA- ATIVIDADE DE ESTERÓIDES INIBIDORES DA AROMATASE E DA 5α-REDUCTASE COMO ANTI-TUMORAIS Faculdade de Farmácia Universidade de Coimbra 2013 Dissertação de candidatura ao Grau de Doutor em Farmácia, Especialidade em Química Farmacêutica, apresentada à Faculdade de Farmácia da Universidade de Coimbra Aos meus pais, Guiomar e Carlos À minha avó Trindade, in memoriam Trabalho realizado sob a orientação do(a) Professor(a) Doutor Elisiário José Tavares da Silva, Faculdade de Farmácia da Universidade de Coimbra Doutora Fernanda Maria Fernandes Roleira, Faculdade de Farmácia da Universidade de Coimbra Doutora Natércia Aurora Almeida Teixeira, Faculdade de Farmácia da Universidade do Porto O presente trabalho foi realizado no Grupo de Química Farmacêutica da Faculdade de Farmácia da Universidade de Coimbra sobre a supervisão do Professor Doutor Elisiário Tavares da Silva e da Professora Doutora Fernanda Roleira, em colaboração com o Departamento de Ciências Biológicas – Laboratório de Bioquímica da Faculdade de Farmácia da Universidade do Porto e com o Grupo de Biologia da Inflamação e Repodução do Instituto de Biologia Molecular e Celular (IBMC) sob a supervisão da Professora Doutora Natércia Teixeira. Uma parte foi realizada no Departmento de Química Orgânica da Faculdade de Farmácia da Universidade de Santiago de Compostela, Espanha. Este trabalho teve o apoio financeiro da Fundação para a Ciência e Tecnologia (FCT) através da atribuição de uma bolsa de doutoramento (SFRH/BD/44872/2008) co-financiada pelo Fundo Social Europeu (FSE) e através da atribuição de um projeto FCOMP-01-0124-FEDER-020970 (PTDC/QUI- BIQ/120319/2010) financiado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do Programa Operacional Factores de Competitividade (COMPETE) e por fundos nacionais através da FCT.
    [Show full text]
  • Module I Oxidation Reactions
    NPTEL – Chemistry – Reagents and Organic reactions Module I Oxidation Reactions Lecture 1 1.1 Osmium Oxidants 1.1.1 Introduction Osmium is the densest (density 22.59 gcm-3) transition metal naturally available. It has seven naturally occurring isotopes, six of which are stable: 184Os, 187Os, 188Os, 189Os, 190Os, and 192Os. It forms compounds with oxidation states ranging from -2 to +8, among them, the most common oxidation states are +2, +3, +4 and +8. Some important osmium catalyzed organic oxidation reactions follow: 1.1.2 Dihydroxylation of Alkenes Cis-1,2-dihydroxylation of alkenes is a versatile process, because cis-1,2-diols are present in many important natural products and biologically active molecules. There are several methods available for cis-1,2-dihydroxylation of alkenes, among them, the OsO4-catalzyed reactions are more valuable (Scheme 1). OsO4 vapours are poisonous and result in damage to the respiratory tract and temporary damage to the eyes. Use OsO4 powder only in a well-ventilated hood with extreme caution. Y. Gao, Encylcopedia of Reagents for Organic Synthesis, John Wiley and Sons, Inc., L. A. Paquette, New York, 1995, 6, 380. OH OsO4 Na2SO3 Et2O, 24 h OH OH OsO4 OH Na2SO3 Et O, 24 h 2 Scheme 1 Joint initiative of IITs and IISc – Funded by MHRD Page 1 of 122 NPTEL – Chemistry – Reagents and Organic reactions The use of tertiary amine such as triethyl amine or pyridine enhances the rate of reaction (Scheme 2). OH OsO4, Pyridine K2CO3, KOH OH Et O, 30 min 2 Scheme 2 Catalytic amount of OsO4 can be used along with an oxidizing agent, which oxidizes the reduced osmium(VI) into osmium(VIII) to regenerate the catalyst.
    [Show full text]
  • Sem-Iii, Core Course-7 Organic Chemistry-3 Topic
    SEM-III, CORE COURSE-7 ORGANIC CHEMISTRY-3 TOPIC: CARBONYL AND RELATED COMPOUNDS Dr. Kalyan Kumar Mandal Associate Professor St. Paul’s C. M. College Kolkata PPT: 4 • OPPENAUER OXIDATION • OXIDATION OF ALCOHOLS WITH PDC AND PCC • PERIODIC ACID AND LEAD TETRAACETATE OXIDATION OF 1,2-GLYCOLS OPPENAUER OXIDATION Oxidation of primary and secondary alcohols to aldehydes and ketones respectively using aluminium tertiary butoxide in presence of a hydride ion acceptor like acetone, cyclohexanone, benzophenone p-benzoquinone, etc., is called Oppenauer oxidation. Facts • In case of oxidation of primary alcohol, non-enolisable ketones with a relatively low reduction potential such as p-benzoquinone is used. • Tertiary butoxide is used as the reagent, since tertiary butanol produced is not oxidised under these conditions. • This reagent is particularly useful for oxidising unsaturated secondary alcohols because it does not affect the double bond. • Primary alcohols including the unsaturated alcohols may also be oxidised to aldehydes if acetone is replaced by p-benzoquinone. • In general, quinones and aromatic ketones are better hydrogen acceptors than acetone. • The reaction is completely reversible and therefore, to shift the reaction towards the product-side, addition of large excess of the hydride acceptor is used. Mechanism • Initially the starting alcohol reacts with aluminium t-butoxide to form a new alkoxide. • This intermediate alkoxide then reacts with acetone or other acceptor molecule and a hydride ion (H-) from the substrate alcohol is transferred to the carbonyl carbon atom of acetone. • The reaction proceeds through the formation of a six-membered cyclic transition state. • The specific (H-) ion transfer from the carbon atom of alcohol molecule to carbonyl carbon atom of acetone has been demonstrated by using RCD(OH)R type labelled alcohol which led to the formation of CH3CD(OH)CH3.
    [Show full text]
  • 17: Oxidation and Reduction
    (11,12/94)(4,5/97)(02,3/07)(01/08) Neuman Chapter 17 17: Oxidation and Reduction 17.1 Oxidation and Reduction Occur Together 17-3 Redox Reactions Involve Electron Transfer (17.1A) 17-3 Inorganic Redox Reactions Organic Redox Reactions Oxidation Levels of Organic Compounds (17.1B) 17-5 Carbon Oxidation Numbers Definitions of Organic Oxidation and Reduction Presentation of Redox Reactions in this Chapter 17.2 Oxidation of Alcohols and Aldehydes 17-6 Oxidation Using Cr(VI) Reagents (17.2A) 17-6 Chromate and Dichromate Reagents Unwanted Oxidation of Aldehydes Jones Oxidation Modified Cr(VI) Reagents Cr(VI) Oxidation Mechanisms Other Inorganic Oxidizing Agents (17.2B) 17-10 MnO2 Sodium Hypochlorite (NaOCl) Organic Oxidizing Agents (17.2C) 17-11 Ketones to Esters Aldehydes to Carboxylic Acids and Alcohols Alcohols to Ketones or Aldehydes 17.3 Oxidation of Carbon-Carbon Multiple Bonds 17-15 Addition of Oxygen to C=C Bonds (17.3A) 17-15 Epoxide Formation Using Peroxyacids Formation of syn-1,2-Diols Using OsO4 or MnO4- Formation of anti-1,2-Diols Oxidative Cleavage of Carbon-Carbon Multiple Bonds (17.3B) 17-17 Cleavage Using Ozone (O3) Cleavage Using CrO3 or KMnO4 Cleavage of 1,2-Diols Using HIO4 or Pb(OAc)4 17.4 Oxidation of Alkyl Groups 17-19 Metal Oxide Oxidations (17.4A) 17-20 KMnO4 and CrO3 Cl2CrO2 SeO2 Oxidations O2 Oxidations (Autoxidation) (17.4B) 17-20 Autoxidation Mechanism Synthetic Utility 1 (11,12/94)(4,5/97)(02,3/07)(01/08) Neuman Chapter 17 17.5 Phenols, Hydroquinones, and Quinones 17-21 Formation of Phenols (17.5A) 17-22 From Cumene
    [Show full text]
  • Oxidation of Alcohols to Aldehydes and Ketones BASIC REACTIONS in ORGANIC SYNTHESIS
    Oxidation of Alcohols to Aldehydes and Ketones BASIC REACTIONS IN ORGANIC SYNTHESIS EDITOR-IN-CHIEF: GABRIEL TOJO DEPARTMENT OF ORGANIC CHEMISTRY, FACULTY OF CHEMISTRY, UNIVERSITY OF SANTIAGO DE COMPOSTELA 15872-SANTIAGO DE COMPOSTELA SPAIN. [email protected] Oxidation of Alcohols to Aldehydes and Ketones: A Guide to Current Common Practice, by Gabriel Tojo and Marcos Ferna´ndez Oxidation of Alcohols to Aldehydes and Ketones A Guide to Current Common Practice GABRIEL TOJO and MARCOS FERNA´ NDEZ Authors: Gabriel Tojo Marcos Ferna´ndez Department of Organic Chemistry Department of Organic Chemistry Faculty of Chemistry Faculty of Chemistry University of Santiago de Compostela University of Santiago de Compostela 15872-Santiago De Compostela 15872-Santiago De Compostela Spain Spain Editor-on-Chief Gabriel Tojo Department of Organic Chemistry Faculty of Chemistry University of Santiago de Compostela 15872-Santiago De Compostela Spain Library of Congress Control Number: 2005927383 ISBN-10: 0-387-23607-4 ISBN-13: 978-0387-23607-0 Printed on acid-free paper. ß2006 Springer ScienceþBusiness Media, Inc. All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer ScienceþBusiness Media, Inc. 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks and similar terms, even if they are not identiWed as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights.
    [Show full text]
  • 6-Oxidation.Pdf
    Myers Oxidation Chem 115 General Introductory References Alkane R-CH3 March, J. In Advanced Organic Chemistry, John Wiley and Sons: New York, 1992, p. 1158! organoboranes RCH BR ' organometallics in general RCH M (M = Li, MgX, ZnX...) 1238. 2 2 2 Carey, F. A.; Sundberg, R. J. In Advanced Organic Chemistry Part B, Plenum Press: New York, organosilanes RCH2SiR3' 1990, p. 615!664. Carruthers, W. In Some Modern Methods of Organic Synthesis 3rd Ed., Cambridge University Press: Cambridge, UK, 1987, p. 344!410. Alcohol R-CH2OH (R-CH2X ) Oxidation States of Organic Functional Groups alkyl halide X = halide alkane sulfonate X = OSO2R' alkyl azide X = N3 The notion of oxidation state is useful in categorizing many organic transformations. This is illustrated by the progression of a methyl group to a carboxylic acid in a series of 2-electron alkylamine X = NR'2 alkylthio ether X = SR' alkyl ether X = OR' oxidations, as shown at right. Included are several functional group equivalents considered to be at the same oxidation state. Summary of Reagents for Oxidative Functional Group Interconversions: Aldehyde (Ketone) R-CHO (RCOR') OH O O NR'' OR'' or R''O OH N 2 N R R'(H) R R' R H hemiketal (hemiacetal) hydrazone oxime R R' R R' alcohol ketone aldehyde R R' R''O OR''' R''O NR2''' Dimethylsulfoxide-Mediated Oxidations Oppenauer Oxidation ketal (acetal) geminal dihalide RCX2R' aminal R R' R R' Dess-Martin Periodinane (DMP) Chromium (VI) Oxidants o-Iodoxybenzoic Acid (IBX) Sodium Hypochlorite R''O R'' N tetra-n-Propylammonium Perruthenate (TPAP) N-Bromosuccinimide
    [Show full text]