ORGANIC CHEMISTRY SEVENTH EDITION L.G.WADE,JR
ABOUT THE AUTHOR L.G."Skip"Wade decided to be romPo Ronald M.Magid AferBrom Rice 1969.Wade went on to Harvard University.where he did research with Pro- While at Harvard,he served as the Head Teaching H.Westheimer. After completing his Ph.D.at Harvard in 1974.Dr.Wade joined the chem te.Dr.Wade dents working toward careers in allareas of hiology.chemistry.human med. icine,veterinary medicine,and environmental studies.He also authored cal education,as well a Dr Wade has been a chemisty teaches organic chemistry and pursues research interests in organic synthe Dr.Wade's interest in forensic science has led him to testify as an expert wit- ness in court cases involving drugs and firearms.and he has worked as a many years. To my students and colleagues at Whitman College
ABOUT THE AUTHOR L. G. "Skip 11 Wade decided to become a chemistry major during his sophomore year at Rice University, while taking organic chemistry from Professor Ronald M. Magid. After receiving his B.A. from Rice in 1969, Wade went on to Harvard University, where he did research with Professor James D. White. While at Harvard, he served as the Head Teaching Fellow for the organic laboratories and was strongly influenced by the teaching methods of two master educators, Professors Leonard K. Nash and Frank H. Westheimer. After completing his Ph.D. at Harvard in 1974, Dr. Wade joined the chemistry faculty at Colorado State University. Over the course of fifteen years at Colorado State, Dr. Wade taught organic chemistry to thousands of students working toward careers in all areas of biology, chemistry, human medicine, veterinary medicine, and environmental studies. He also authored research papers in organic synthesis and in chemical education, as well as eleven books reviewing current research in organic synthesis. Since 1989, Dr. Wade has been a chemistry professor at Whitman College, where he teaches organic chemistry and pursues research interests in organic synthesis and forensic chemistry. Dr. Wade received the A. E. Lange Award for Distinguished Science Teaching at Whitman in 1993. Dr. Wade's interest in forensic science has led him to testify as an expert witness in court cases involving drugs and firearms, and he has worked as a police firearms instructor, drug consultant, and boating safety officer. He also enjoys repairing and restoring old violins and bows, which he has done professionally for many years. To my students and colleagues at Whitman College
CONTENTS Preface xxii About the Author ii 1 INTRODUCTION AND REVIEW 1 1-1 The Origins of Organic Chemistry I 1-2 Principles of Atomie Structure 3 1-3 Bond Formation:The Octet Rule 6 1-4 Lewis Structures 7 1-5 Multiple Bonding 8 Summary:Common Bonding Patterns (Uncharged)9 1-9 Resonance 13 1-10 Structural Formulas 17 1-l1 Molecular Formulas and Empirical Formulas 20 1-12 Arrhenius Acids and Bases 21 1-13 Bronsted-Lowry Acids and Bases 22 4 Lewis Acids and Bases29 Chapter I Glossary 32 Study Problems 34 STRUCTURE AND PROPERTIES 2 OF ORGANIC MOLECULES 40 2-1 Wave Properties of Electrons in Orbitals 40 2-2 Molecular Orbitals 42 2-3 Pi Bonding 45 2.4 Hybridization and Molecular Shapes 46 2-5 Drawing Three-Dimensional Molecules 50 General Rules of Hybridization and Geometry 51 Bond Rotation 55 onds and Mo 212 2.130 2.14 anic Co n74 Chapter 2 Glo Study Problems 79
CONTENTS vi Preface xxii About the Author 111 1 INTRODUCTION AND REVIEW 1 1-1 The Origins of Organic Chemistry 1 1-2 Principles of Atomic Structure 3 1-3 Bond Formation: The Octet Rule 6 1-4 Lewis Structures 7 1-5 Multiple Bonding 8 Summary: Common Bonding Patterns (Uncharged) 9 1-6 Electronegativity and Bond Polarity 9 1-7 Formal Charges 10 1-8 Ionic Structures 12 Summary: Common Bonding Patterns in Organic Compounds and Ions 13 1-9 Resonance 13 1-10 Structural Formulas 17 1-11 Molecular Formulas and Empirical Formulas 20 1-12 Arrhenius Acids and Bases 21 1-13 Bronsted-Lowry Acids and Bases 22 1-14 Lewis Acids and Bases 29 Chapter 1 Glossary 32 Study Problems 34 STRUCTURE AND PROPERTIES 2 OF ORGANIC MOLECULES 40 2-1 Wave Properties of Electrons in Orbitals 40 2-2 Molecular Orbitals 42 2-3 Pi Bonding 45 2-4 Hybridization and Molecular Shapes 46 2-5 Drawing Three-Dimensional Molecules 50 2-6 General Rules of Hybridization and Geometry 51 2-7 Bond Rotation 55 2-8 Isomerism 57 2-9 Polarity of Bonds and Molecules 59 2-10 Intermolecular Forces 62 2-11 Polarity Effects on Solubilities 66 2-12 Hydrocarbons 69 2-13 Organic Compounds Containing Oxygen 72 2-14 Organic Compounds Containing Nitrogen 74 Chapter 2 Glossary 76 Study Problems 79
Contents 3 STRUCTURE AND STEREOCHEMISTRY OF ALKANES 83 3-1 Classification of Hydrocarbons(Review)83 3-2 Molecular Formulas of Alkanes 84 3-3 Nomenclature of Alkanes 85 Summary:Rules for Naming Alkanes 90 anes 93 1 s of Alkanes 9 e100 ations of Higher 3-10 Cycloalkanes 102 3-11 cis-trans Isomerism in Cycloalkanes 105 3-12 Stabilities of Cycloalkanes:Ring Strain 105 3-13 Cyclohexane Conformations 109 roblem-Soving Strategy:Drawing Chair 3-14 Conformations of Monosubstituted Cyclohexanes I13 3-15 Conformations of Disubstituted Cyclohexanes 116 Problem-Solving trateg:cis 3-16 Bicyclic Molecules 119 Chapter 3 Glossary 121 Study Problems 124 4 THE STUDY OF CHEMICAL REACTIONS 127 4-1 Introduction 127 4-2 Chlorination of Methane 127 4-3 The Free-Radical Chain Reaction 128 Key Mechanism:Free-Radical Halogenation 130 4-4 Equilibrium Constants and Free Energy 132 Enthalpy and Entropy 135 Bond-Dissociation Enthalpies 136 Enthalpy Cha Activation eeuation /39 K Temperature Dependence 4-10 Transition States 142 4-11 Rates of Multistep Reactions 144 4-12 Temperature Dependence of Halogenation 145 4-13 Selectivity in Halogenation 146 4-14 The Hammond Postulate 151 Strategy:Proposing Reaction 4-15 Radical Inhibitors 155 4-16 Reactive Intermediates 156 Summary:Reactive Intermediates 162 Chapter 4 Glossary 162 Study Problems 165
3 STRUCTURE AND STEREOCHEMISTRY OF ALKANES 83 3-1 Classification of Hydrocarbons (Review) 83 3-2 Molecular Formulas of Alkanes 84 3-3 Nomenclature of Alkanes 85 Summary: Rules for Naming Alkanes 90 3-4 Physical Properties of Alkanes 91 3-5 Uses and Sources of Alkanes 93 3-6 Reactions of Alkanes 95 3-7 Structure and Conformations of Alkanes 96 3-8 Conformations of Butane 100 3-9 Conformations of Higher Alkanes 102 3-10 Cycloalkanes 102 3-11 cis-trans Isomerism in Cycloalkanes 105 3-12 Stabilities of Cycloalkanes; Ring Strain 105 3-13 Cyclohexane Conformations 109 Problem-Solving Strategy: Drawing Chair Conformations 112 3-14 Conformations of Monosubstituted Cyclohexanes 113 3-15 Conformations ofDisubstituted Cyclohexanes 116 Problem-Solving Strategy: Recognizing cis and trans Isomers 118 3-16 Bicyclic Molecules 119 Chapter 3 Glossary 121 Study Problems 124 4 THE STUDY OF CHEMICAL REACTIONS 127 4-1 Introduction 127 4-2 Chlorination of Methane 127 4-3 The Free-Radical Chain Reaction 128 Key Mechanism: Free-Radical Halogenation 130 4-4 Equilibrium Constants and Free Energy 132 4-5 Enthalpy and Entropy 135 4-6 Bond-Dissociation Enthalpies 136 4-7 Enthalpy Changes in Chlorination 137 4-8 Kinetics and the Rate Equation 139 4-9 Activation Energy and the Temperature Dependence of Rates 141 4-10 Transition States 142 4-11 Rates of Multistep Reactions 144 4-12 Temperature Dependence of Halogenation 145 4-13 Selectivity in Halogenation 146 4-14 The Hammond Postulate 151 Problem-Solving Strategy: Proposing Reaction Mechanisms 153 4-15 Radical Inhibitors 155 4-16 Reactive Intermediates 156 Summary: Reactive Intermediates 162 Chapter 4 Glossary 162 Study Problems 165 Contents vii
Contents STEREOCHEMISTRY 169 17元 5.3 (R) ature of Asymmetric Carbon Atoms 176 ation of Enantiomers 186 56 Racemic Mixtures 187 and Optical Purity 188 5-8 Chirality of Conformationally Mobile Systems 189 5-9 Chiral Compounds without Asymmetric Atoms 191 5-10 Fischer Projections 193 Summary:Fischer Projections and Their Use 198 5-11 Diastercomers 198 Summary:Types of Isomers 199 Stereochemistry of Molecules with Two or More Asymmetric Carbons 200 eso Comp 0 nfiguration 20 mers 5-16 Study Problems 211 ALKYL HALIDES:NUCLEOPHILIC SUBSTITUTION O AND ELIMINATION 215 Introduction 215 6-3 Halides 216 Halides 218 re of Alkvl Halides 220 6-5 Physical Pr s of alkyl Halides 221 aration of Alky]Halides 223 Summary:Methods for Preparing Alkyl Halides 226 6.7 Reactions of Alkyl Halides:Substitution and Elimination 228 6-8 Second-Order Nucleophilic Substitution:The S2 Reaction 229 Key Mechanism:The SN2 Reaction 230 69 Generality of the SN2 Reaction 23 Summary:Sy2 Reactions of Alkyl Halides 231 6-10 Factors Affecting Reactions:Strength of the Nucleophile 233 n Nucleophilic city 234 keactivity of the S SN2 R ions 237 em the on ey Me SNI Reaction 243 244 6.14 of the s 47 615 nts in S.1 Reactions249 6-16 Comparison of Sxl and Sx2 Reactions 252 6.17 First-Order Elimination:The El Reaction 25: Key Mechanism:The E1 Reaction 255 Summary:Carbocation Reactions 259
viii Contents 5 STEREOCHEMISTRY 169 5-1 Introduction 169 5-2 Chirality 170 5-3 (R) and (S) Nomenclature of Asymmetric Carbon Atoms 176 5-4 Optical Activity 181 5-5 Biological Discrimination of Enantiomers 186 5-6 Racemic Mixtures 187 5-7 Enantiomeric Excess and Optical Purity 188 5-8 Chirality of Conformationally Mobile Systems 189 5-9 Chiral Compounds without Asymmetric Atoms 191 5-10 Fischer Projections 193 Summary: Fischer Projections and Their Use 198 5-11 Diastereomers 198 Summary: Types oflsomers 199 5-12 Stereochemistry of Molecules with Two or More Asymmetric Carbons 200 5-13 Meso Compounds 201 5-14 Absolute and Relative Configuration 203 5-15 Physical Properties of Diastereomers 205 5-16 Resolution of Enantiomers 206 Chapter 5 Glossary 209 Study Problems 211 6 ALKYL HALIDES: NUCLEOPHILIC SUBSTITUTION AND ELIMINATION 215 6-1 Introduction 215 6-2 Nomenclature of Alkyl Halides 216 6-3 Common Uses of Alkyl Halides 218 6-4 Structure of Alkyl Halides 220 6-5 Physical Properties of Alkyl Halides 221 6-6 Preparation of Alkyl Halides 223 Summary: Methods for Preparing Alkyl Halides 226 6-7 Reactions of Alkyl Halides: Substitution and Elimination 228 6-8 Second-Order Nucleophilic Substitution: The SN2 Reaction 229 Key Mechanism: The SN2 Reaction 230 6-9 Generality of the SN2 Reaction 231 Summary: SN2 Reactions of Alkyl Halides 231 6-10 Factors Affecting SN2 Reactions: Strength of the Nucleophile 233 Summary: Trends in Nucleophilicity 234 6-11 Reactivity of the Substrate in SN2 Reactions 237 6-12 Stereochemistry of the SN2 Reaction 241 6-13 First-Order Nucleophilic Substitution: The SN 1 Reaction 243 Key Mechanism: The SN 1 Reaction 244 6-14 Stereochemistry of the SNI Reaction 247 6-15 Rearrangements in SNI Reactions 249 6-16 Comparison of SNI and SN2 Reactions 252 Summary: Nucleophilic Substitutions 254 6-17 First-Order Elimination: TheEl Reaction 255 Key Mechanism: The E1 Reaction 255 Summary: Carbocation Reactions 259
Contents 6-18 Positional Orientation of elimination:Zaitsey's rule 260 6-19 Second-Order Elimination:The E2 Reaction 261 Key Mechanism:The E2 Reaction 262 6-20 Stereochemistry of the E2 Reaction 264 6-21 Comparison of El and E2 Elimination Mechanisms 265 Summary:Elimination Reactions 267 Problem-Solving Strategy:Predic ting Substitutions and Eliminations 267 Summary:Reactions of Alkyl Halides 270 6w27632 7 STRUCTURE AND SYNTHESIS OF ALKENES 281 7-1 Introduction The Orbital Description of the Alkene Double Bond 282 7.5 287 7.6 e of Alkenes 290 7-7 Stability of Alkenes 292 7-8 Physical Properties of Alkenes 298 7-9 Alkene Synthesis by Elimination of Alkyl Halides 300 7-10 Alkene Synthesis by Dehydration of Alcohols 308 ed-Catalyed 7-11 by Hig h-Temperrd Sum ds for nthesis of Alkenes 316 Chanter Glos ary 317 Study Problems 319 8REACTIONS OF ALKENES 323 to Al Key Mechanism:Electrophilic Addition to Alkenes 324 8-3 Addition of Hydrogen Halides to Alkenes 326 8-4 Addition of Water:Hydration of Alkenes 332 8-5 Hydration by Oxymercuration-Demercuration 335 8-6 Alkoxymercuration-Demercuration 337 8-1 Hydroboration of Alkenes 338 8-8 Addition of Ha ogens to Alk es344 8-9 Formation of Halohydrins 347 8-10 Catalytic Hydrogenationo enes to A cnes 352 des 357 9 15 Oxidati ylation 8-16 365 8-17 Olefin Metathesis 369
6-18 Positional Orientation of Elimination: Zaitsev's Rule 260 6-19 Second-Order Elimination: The E2 Reaction 261 Key Mechanism: The E2 Reaction 262 6-20 Stereochemistry of the E2 Reaction 264 6-21 Comparison of E1 and E2 Elimination Mechanisms 265 Summary: Elimination Reactions 267 Problem-Solving Strategy: Predicting Substitutions and Eliminations 267 Summary: Reactions of Alkyl Halides 270 Chapter 6 Glossary 273 Study Problems 276 7 STRUCTURE AND SYNTHESIS OF ALKENES 281 7-1 Introduction 281 7-2 The Orbital Description of the Alkene Double Bond 282 7-3 Elements of Unsaturation 283 7-4 Nomenclature of Alkenes 285 7-5 Nomenclature of Cis-Trans Isomers 287 Summary: Rules for Naming Alkenes 289 7-6 Commercial Importance of Alkenes 290 7-7 Stability of Alkenes 292 7-8 Physical Properties of Alkenes 298 7-9 Alkene Synthesis by Elimination of Alkyl Halides 300 7-10 Alkene Synthesis by Dehydration of Alcohols 308 Key Mechanism: Acid-Catalyzed Dehydration of an Alcohol 309 7-11 Alkene Synthesis by High-Temperature Industrial Methods 311 Problem-Solving Strategy: Proposing Reaction Mechanisms 312 Summary: Methods for Synthesis of Alkenes 316 Chapter 7 Glossary 317 Study Problems 319 8 REACTIONS OF ALKENES 323 8-1 Reactivity of the Carbon-Carbon Double Bond 323 8-2 Electrophilic Addition to Alkenes 324 Key Mechanism: Electrophilic Addition to Alkenes 324 8-3 Addition of Hydrogen Halides to Alkenes 326 8-4 Addition of Water: Hydration of Alkenes 332 8-5 Hydration by Oxymercuration-Demercuration 335 8-6 Alkoxymercuration-Demercuration 337 8-7 Hydroboration of Alkenes 338 8-8 Addition of Halogens to Alkenes 344 8-9 Formation of Halohydrins 347 8-10 Catalytic Hydrogenation of Alkenes 350 8-11 Addition of Carbenes to Alkenes 352 8-12 Epoxidation of Alkenes 355 8-13 Acid-Catalyzed Opening of Epoxides 357 8-14 Syn Hydroxylation of Alkenes 360 8-15 Oxidative Cleavage of Alkenes 362 8-16 Polymerization of Alkenes 365 8-17 Olefin Metathesis 369 Contents ix
Contents Problem-Solving Strategy:Organic Synthesis 372 Summary:Reactions of Alkenes 374 Chapter 8 Glossary 379 Study Problems 382 O ALKYNES 388 9-1 Introduction 388 9-2 Nomenclature of Alkynes 389 9-3 Physical Pro erties of Alkynes 390 9.4 Commercial Importance of Alkynes 390 9-5 Electronic Structure of Alkynes 392 9-6 Acidity of Alkynes:Formation of Acetylide Ions 393 9-7 Synthesis of Alkynes from Acetylides 395 9-8 Synthesis of Alkynes by Elimination Reactions 399 Summary:Syntheses of Alkynes Addition F Summary:Reactions of Alkynes 414 Chapter 9 Glossary 417 Study Problems 418 10 STRUCTURE AND SYNTHESIS OF ALCOHOLS 421 Introduction 42 Structure and Cl sification of Alcohol 2 ture of Alco Physical ies of Al hals Acidity of Alcoh 43 10-7Sy the is of Alcohols:In and Review 434 Summary:Previous Alcohol sv 10-8 Organometallic Reagents for Alcohol Synthesis 436 10-9 Addition of Organometallic Reagents to Carbonyl Compounds 439 Key Mechanism:Grignard Reactions 439 Summary:Grignard Reactions 446 10-10 Side Reactions of Organometallic Reagents:Reduction of Alkyl Halides 447 10-11 Reduction of the Carbonyl Group:Synthesis of 1 and 2 Alcohols 449 Summary:Reactions of LiAlH,and NaBH 452 10-12 Thiols (Mercaptans)455 Chapter 10 Glossary 457 Study Problems 459 11 REACTIONS OF ALCOHOLS 464 11-1 Oxidation State es of Alcohols and Related Functional Groups 46 idizing Alcohols 469
x Contents Problem-Solving Strategy: Organic Synthesis 372 Summary: Reactions of Alkenes 374 Chapter 8 Glossary 379 Study Problems 382 9 ALKYN ES 388 9-1 Introduction 388 9-2 Nomenclature of Alkynes 389 9-3 Physical Properties of Alkynes 390 9-4 Commercial Importance of Alkynes 390 9-5 Electronic Structure of Alkynes 392 9-6 Acidity of Alkynes; Formation of Acetylide Ions 393 9-7 Synthesis of Alkynes from Acetylides 395 9-8 Synthesis of Alkynes by Elimination Reactions 399 Summary: Syntheses of Alkynes 400 9-9 Addition Reactions of Alkynes 40 l 9-10 Oxidation of Alkynes 411 Problem-Solving Strategy: Multistep Synthesis 413 Summary: Reactions of Alkynes 414 Chapter 9 Glossary 417 Study Problems 418 1 Q STRUCTURE AND SYNTHESIS OF ALCOHOLS 421 10-1 Introduction 421 10-2 Structure and Classification of Alcohols 421 10-3 Nomenclature of Alcohols and Phenols 423 10-4 Physical Properties of Alcohols 427 10-5 Commercially Important Alcohols 429 10-6 Acidity of Alcohols and Phenols 431 10-7 Synthesis of Alcohols: Introduction and Review 434 Summary: Previous Alcohol Syntheses 434 10-8 Organometallic Reagents for Alcohol Synthesis 436 10-9 Addition of Organometallic Reagents to Carbonyl Compounds 439 Key Mechanism: Grignard Reactions 439 Summary: Grignard Reactions 446 10-10 Side Reactions of Organometallic Reagents: Reduction of Alkyl Halides 447 10-11 Reduction of the Carbonyl Group: Synthesis of 1 o and 2° Alcohols 449 Summary: Reactions of LiAlH4 and NaBH4 452 Summary: Alcohol Syntheses by Nucleophilic Additions to Carbonyl Groups 453 10-12 Thiols (Mercaptans) 455 Chapter 10 Glossary 457 Study Problems 459 11 REACTIONS OF ALCOHOLS 464 11-1 Oxidation States of Alcohols and Related Functional Groups 464 11-2 Oxidation of Alcohols 466 11-3 Additional Methods for Oxidizing Alcohols 469
Contents xi 11-4 Biological Oxidation of Alcohols 471 11-5 Alcohols as Nucleophiles and Electrophiles:Formation of Tosylates 472 Summary:S.2 Reactions of Tosylate Esters 475 11-6 Reduction of Alcohols 475 11-7 Reactions of Alcohols with Hydrohalic Acids 476 11-8 Reactions of Alcohols with Phosphorus Halides 48 11-9 Reactions of Alcohols with Thionyl Chloride 482 11-10 Dehydration Reactions of Alcohols 484 oposing Reaction Mechanisms 488 iomofAeohois49g 13 ers of In nic Acids 494 11-14 40 Mechanism:The Williamson Ether Synthesis 497 Problem-Solving Strategy:Multiste p Synthesis 499 Summary:Reactions of Alcohols 502 Chapter II Glossary 504 Study Problems 506 INERARED SPECTROSCOPY AND MASS 12 SPECTROMETRY 510 Introduction 510 ctrum5 125 -Active and R Vibrations 515 trum 516 138 ols and amines 524 risti Absortions of Carbonyl Com ounds 525 12-10 Charaeteristic Absomtions ofC-N Bonds 531 12-11 Simplified Summary of IR Stretching Frequencies 532 12-12 Reading and Interpreting IR Spectra(Solved Problems)534 12-13 Introduction to Mass Spectrometry 539 12-14 Determination of the Molecular Formula by Mas B5” 13 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 561 13-1 Introduction 561 13-2 Theory of Nuclear Magnetic Resonance 561 13-3 Magnetic Shielding by Electrons 564 13-4 The NMR Spectrometer 566 13-5 The Chemical Shift 567 The Number of Signals 574 Areas of the Peaks 575
11-4 Biological Oxidation of Alcohols 471 11-5 Alcohols as Nucleophiles and Electrophiles; Formation of Tosylates 472 Summary: SN2 Reactions of Tosylate Esters 475 11-6 Reduction of Alcohols 475 11-7 Reactions of Alcohols with Hydrohalic Acids 476 11-8 Reactions of Alcohols with Phosphorus Halides 481 11-9 Reactions of Alcohols with Thionyl Chloride 482 11-10 Dehydration Reactions of Alcohols 484 Problem-Solving Strategy: Proposing Reaction Mechanisms 488 11-11 Unique Reactions ofDiols 491 11-12 Esterification of Alcohols 493 11-13 Esters oflnorganic Acids 494 11-14 Reactions of Alkoxides 497 Key Mechanism: The Williamson Ether Synthesis 497 Problem-Solving Strategy: Multistep Synthesis 499 Summary: Reactions of Alcohols 502 Chapter 11 Glossary 504 Study Problems 506 INFRARED SPECTROSCOPY AND MASS 12 SPECTROMETRY 510 12-1 Introduction 510 12-2 The Electromagnetic Spectrum 511 12-3 The Infrared Region 512 12-4 Molecular Vibrations 513 12-5 IR-Active and IR-Inactive Vibrations 515 12-6 Measurement of the IR Spectrum 516 12-7 Infrared Spectroscopy of Hydrocarbons 519 12-8 Characteristic Absorptions of Alcohols and Amines 524 12-9 Characteristic Absorptions of Carbonyl Compounds 525 12-10 Characteristic Absorptions of C-N Bonds 531 12-11 Simplified Summary ofiR Stretching Frequencies 532 12-12 Reading and Interpreting IR Spectra (Solved Problems) 534 12-13 Introduction to Mass Spectrometry 539 12-14 Determination of the Molecular Formula by Mass Spectrometry 543 12-15 Fragmentation Patterns in Mass Spectrometry 546 Summary: Common Fragmentation Patterns 551 Chapter 12 Glossary 553 Study Problems 554 13 NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 561 13-1 Introduction 561 13-2 Theory of Nuclear Magnetic Resonance 561 13-3 Magnetic Shielding by Electrons 564 13-4 The NMR Spectrometer 566 13-5 The Chemical Shift 567 13-6 The Number of Signals 574 13-7 Areas of the Peaks 575 Contents xi
x Contents 13-8 Spin-Spin Splitting 578 Problem-Solving Strategy:Drawing an NMR Spectrum 583 13-9 Complex Splitting 587 Stereochemical Nonequivalence of Protons590 13-11 n NMR Spectra 596 13.12 Carbon-13 NMR Sp 601 13.131 ting Carbon NMR Sp ctra 609 13-14 e Imaging 611 Problem-Solving Strategy:Spectroscopy Problems 612 Chapter 13 Glossary 616 Study Problems 618 14 ETHERS,EPOXIDES,AND SULFIDES 625 14-1 Introduction 625 14-2 Physical Properties of Ethers 625 14-3 Nomenclature of Ethers 630 144 Spectroscopy of Ethers 633 14-5 The Williamson Ether Synthesis 635 Synthesis of Ethers by Alkoxymercuration-Demercuration 636 14-7 Industrial Synthesis:Bimolecular Dehydration of Alcohols 637 Summary:Syntheses of Ethers(Review)638 148 Cleavage of Ethers by HBr and HI 638 14- on of Ethers thers 641 1410 eonsorB 1411 ses 647 1413 ed Ring 14-13 Base-Catalyzed Ring ening of Epoxides64 of Epoxides 651 14-14 Orientation of Epoxide Ring Opening 652 14.15 reactions of epoxides with grignard and orea olithium Reagents 654 14.16 Epoxy Resins:The Advent of Modern Glues 655 Sunmmry:Reactions of Epuxides 657 Chapter 14 Glossary 658 Study Problems 660 CoNJUGATED SYSTEMS ORBITAL SYMMETRY 15 AND ULTRAVIOLET SPECTROSCOPY 665 15-1 Introduction 665 of Dienes 665 15-3 Molecular Orbital Picture of a Conjugated System 667 15-4 Allylic Cations 671 15-5 1.2-and 1.4-Addition to Conjugated Dienes 672 15-6 Kinetic versus Thermodynamic Control in the Addition of HBr 1.3-Butadiene 674 Allylic Radical 670 ecular Orbitals of the Allylic System 678
xii Contents 13-8 Spin-Spin Splitting 578 Problem-Solving Strategy: Drawing an NMR Spectrum 583 13-9 Complex Splitting 587 13-10 Stereochemical Nonequivalence of Protons 590 13-11 Time Dependence of NMR Spectroscopy 593 Problem-Solving Strategy: Interpreting Proton NMR Spectra 596 13-12 Carbon-13 NMR Spectroscopy 601 13-13 Interpreting Carbon NMR Spectra 609 13-14 Nuclear Magnetic Resonance Imaging 611 Problem-Solving Strategy: Spectroscopy Problems 612 Chapter 13 Glossary 616 Study Problems 618 14 ETHERS, EPOXIDES, AND SULFIDES 625 14-1 Introduction 625 14-2 Physical Properties of Ethers 625 14-3 Nomenclature of Ethers 630 14-4 Spectroscopy of Ethers 633 14-5 The Williamson Ether Synthesis 635 14-6 Synthesis of Ethers by Alkoxymercuration-Demercuration 636 14-7 Industrial Synthesis: Bimolecular Dehydration of Alcohols 637 Summary: Syntheses of Ethers (Review) 638 14-8 Cleavage of Ethers by HBr and HI 638 14-9 Autoxidation of Ethers 641 Summary: Reactions of Ethers 641 14-10 Sulfides (Thioethers) 642 14-11 Synthesis of Epoxides 644 Summary: Epoxide Syntheses 647 14-12 Acid-Catalyzed Ring Opening of Epoxides 648 14-13 Base-Catalyzed Ring Opening of Epoxides 651 14-14 Orientation of Epoxide Ring Opening 652 14-15 Reactions of Epoxides with Grignard and Organolithium Reagents 654 14-16 Epoxy Resins: The Advent of Modern Glues 655 Summary: Reactions of Epoxides 657 Chapter 14 Glossary 658 Study Problems 660 5 CONJUGATED SYSTEMS, ORBITAL SYMMETRY, 1 AND ULTRAVIOLET SPECTROSCOPY 665 15-1 Introduction 665 15-2 Stabilities of Dienes 665 15-3 Molecular Orbital Picture of a Conjugated System 667 15-4 Allylic Cations 671 15-5 1,2- and 1,4-Addition to Conjugated Dienes 672 15-6 Kinetic versus Thermodynamic Control in the Addition of HBr to 1,3-Butadiene 674 15-7 Allylic Radicals 676 15-8 Molecular Orbitals of the Allylic System 678
Contents 15-9 Electronic Configurations of the allyl radical.cation.and Anion 680 15-10 Sx2 Displacement Reactions of Allylic Halides and Tosylates 681 15-11 The Diels-Alder Reaction 682 Key Mechanism:The Diels-Alder Reacticn 682 15-12 The Diels-Alder as an Example of a Pericyclic Reaction 691 15-13 Ultraviolet Absorption Spectroscopy 694 Chapter 15 Glossary 701 Study Problems 703 16 AROMATIC COMPOUNDS 707 16-1 Introduction:The Discovery of Benzene 707 16-2 The Structure and Properties of Benzene 707 16-3 The Molecular Orbitals of Benzene 711 16-4 The Molecular Orbital Picture of Cyclobutadiene 714 16-5 Aromatic.Antiaromatic,and Nonaromatie Compounds 716 16-6 Htickel's Rule 716 Molecular Orbital Derivation of Huckel's Rule 718 16-9 Aromatic Tons 719 Aromatic Compounds 72 f 16-1 Fused He 16.13 s734 16-14 Physical Pro ies of ber e and Its De ivatives 736 16-15 Spe d73 Chapter 16 Glossary 740 Study Problems 742 17 REACTIONS OF AROMATIC COMPOUNDS 75 17- Aromat Nitration of Be n of Benzene 757 17-5 Nitration of Toluene:The Effect of Alkyl Substitution759 17-6 Activating.Ortho.Para-Directing Substituents 761 Summary:Activating,Ortho.Para-Directors 764 17-7 Deactivating.Meta-Directing Substituents 765 Summary:Deactivating.Meta-Directors 768 17-8 Halogen Substituents:Deactivating.but Ortho.Para-Directing 768 Summary:Directing Effects of Substituents 770 179 Effects of Multiple Substi uents on Electrophilic 17-10 The EriedeL-Cr 17-11 The Friedel-Crafts Acy 777 son of Friedel-Crafts Alkylation and Aeylation 780 17-12 Nucleophilic Aromatic Substitution 782
15-9 Electronic Configurations of the Allyl Radical, Cation, and Anion 680 15-10 SN2 Displacement Reactions of Allylic Halides and Tosylates 681 15-11 The Diels-Alder Reaction 682 Key Mechanism: The Diels-Aider Reaction 682 15-12 The Diels-Alder as an Example of a Pericyclic Reaction 691 15-13 Ultraviolet Absorption Spectroscopy 694 Chapter 15 Glossary 701 Study Problems 703 16 AROMATIC COMPOUNDS 707 16-1 Introduction: The Discovery of Benzene 707 16-2 The Structure and Properties of Benzene 707 16-3 The Molecular Orbitals of Benzene 711 16-4 The Molecular Orbital Picture of Cyclobutadiene 714 16-5 Aromatic, Antiaromatic, and Nonaromatic Compounds 716 16-6 Htickel's Rule 716 16-7 Molecular Orbital Derivation of Htickel's Rule 718 16-8 Aromatic Ions 719 16-9 Heterocyclic Aromatic Compounds 725 16-10 Polynuclear Aromatic Hydrocarbons 729 16-11 Aromatic Allotropes of Carbon 731 16-12 Fused Heterocyclic Compounds 733 16-13 Nomenclature of Benzene Derivatives 734 16-14 Physical Properties of Benzene and Its Derivatives 736 16-15 Spectroscopy of Aromatic Compounds 737 Chapter 16 Glossary 740 Study Problems 742 17 REACTIONS OF AROMATIC COMPOUNDS 751 17-1 Electrophilic Aromatic Substitution 751 Key Mechanism: Electrophilic Aromatic Substitution 752 17-2 Halogenation of Benzene 753 17-3 Nitration of Benzene 755 17-4 Sulfonation of Benzene 757 17-5 Nitration of Toluene: The Effect of Alkyl Substitution 759 17-6 Activating, Ortho, Para-Directing Substituents 761 Summary: Activating, Ortho, Para-Directors 764 17-7 Deactivating, Meta-Directing Substituents 765 Summary: Deactivating, Meta-Directors 768 17-8 Halogen Substituents: Deactivating, but Ortho, Para-Directing 768 Summary: Directing Effects of Substituents 770 17-9 Effects of Multiple Substituents on Electrophilic Aromatic Substitution 770 17-10 The Friedel-Crafts Alkylation 773 17-11 The Friedel-Crafts Acylation 777 Summary: Comparison of Friedel-Crafts Alkylation and Acylation 780 17-12 Nucleophilic Aromatic Substitution 782 Contents xiii