《有机化学》课程教学资源（参考书籍）Organic Chemistry, 8th ed 2017, Paula Yurkanis Bruice, University Of California Santa Barbara.pdf_大学文库

vi Medical Connections Fosamax Prevents Bones from Being Nibbled Away (2.8) Aspirin Must Be in its Basic Form to be Physiologically Active (2.10) Blood: A Buffered Solution (2.11) Drugs Bind to Their Receptors (3.9) Cholesterol and Heart Disease (3.16) How High Cholesterol is Treated Clinically (3.16) The Enantiomers of Thalidomide (4.17) Synthetic Alkynes Are Used to Treat Parkinson’s Disease (7.0) Synthetic Alkynes Are Used for Birth Control (7.1) The Inability to Perform an SN2 Reaction Causes a Severe Clinical Disorder (10.3) Treating Alcoholism with Antabuse (10.5) Methanol Poisoning (10.5) Anesthetics (10.6) Alkylating Agents as Cancer Drugs (10.11) S-Adenosylmethionine: A Natural Antidepressant (10.12) Artificial Blood (12.12) Nature’s Sleeping Pill (15.1) Penicillin and Drug Resistance (15.12) Dissolving Sutures (15.13) Cancer Chemotherapy (16.17) Breast Cancer and Aromatase Inhibitors (17.12) Thyroxine (18.3) A New Cancer-Fighting Drug (18.20) Atropine (19.2) Porphyrin, Bilirubin, and Jaundice (19.7) Measuring the Blood Glucose Levels in Diabetes (20.8) Galactosemia (20.15) Why the Dentist is Right (20.16) Resistance to Antibiotics (20.17) Heparin–A Natural Anticoagulant (20.17) Amino Acids and Disease (21.2) Diabetes (21.8) Diseases Caused by a Misfolded Protein (21.15) How Tamiflu Works (22.11) Assessing the Damage After a Heart Attack (23.5) Cancer Drugs and Side Effects (23.7) Anticoagulants (23.8) Phenylketonuria (PKU): An Inborn Error of Metabolism (24.8) Alcaptonuria (24.8) Multiple Sclerosis and the Myelin Sheath (25.5) How Statins Lower Cholesterol Levels (25.8) One Drug—Two Effects (25.10) Sickle Cell Anemia (26.9) Antibiotics That Act by Inhibiting Translation (26.9) Antibiotics Act by a Common Mechanism (26.10) Health Concerns: Bisphenol A and Phthalates (27.11) Biological Connections Poisonous Amines (2.3) Cell Membranes (3.10) How a Banana Slug Knows What to Eat (7.2) Electron Delocalization Affects the Three-Dimensional Shape of Proteins (8.4) Naturally Occurring Alkyl Halides That Defend Against Predators (9.5) Biological Dehydrations (10.4) Alkaloids (10.9) Dalmatians: Do Not Fool with Mother Nature (15.11) A Semisynthetic Penicillin (15.12) Preserving Biological Specimens (16.9) A Biological Friedel-Crafts Alkylation (18.7) A Toxic Disaccharide (20.15) Controlling Fleas (20.16) Primary Structure and Taxonomic Relationship (21.12) Competitive Inhibitors (23.7) Whales and Echolocation (25.3) Snake Venom (25.5) Cyclic AMP (26.1) There Are More Than Four Bases in DNA (26.7) Chemical Connections Natural versus Synthetic Organic Compounds (1.0) Diamond, Graphite, Graphene, and Fullerenes: Substances that Contain Only Carbon Atoms (1.8) Water—A Unique Compound (1.12) Acid Rain (2.2) Derivation of the Henderson-Hasselbalch Equation (2.10) Bad-Smelling Compounds (3.7) Von Baeyer, Barbituric Acid, and Blue Jeans (3.12) Starch and Cellulose—Axial and Equatorial (3.14) Cis-Trans Interconversion in Vision (4.1) The Difference between ∆G‡ and Ea (5.11) Calculating Kinetic Parameters (End of Ch 05) Borane and Diborane (6.8) Cyclic Alkenes (6.13) Chiral Catalysts (6.15) Sodium Amide and Sodium in Ammonia (7.10) Buckyballs (8.18) Why Are Living Organisms Composed of Carbon Instead of Silicon? (9.2) Solvation Effects (9.14) The Lucas Test (10.1) Crown Ethers—Another Example of Molecular Recognition (10.7) Crown Ethers Can be Used to Catalyze SN2 Reactions (10.7) Eradicating Termites (10.12) Cyclopropane (12.9) What Makes Blueberries Blue and Strawberries Red? (13.22) Nerve Impulses, Paralysis, and Insecticides (15.19) Enzyme-Catalyzed Carbonyl Additions (16.4) Carbohydrates (16.9) b-Carotene (16.13) Synthesizing Organic Compounds (16.14) Enzyme-Catalyzed Cis-Trans Interconversion (16.16) Incipient Primary Carbocations (18.7) Hair: Straight or Curly? (21.8) Right-Handed and Left-Handed Helices (21.14) b-Peptides: An Attempt to Improve on Nature (21.14) Why Did Nature Choose Phosphates? (24.1) Protein Prenylation (25.8) Bioluminescence (28.6) Complete List of In-Chapter Connection Features

vii Pharmaceutical Connections Chiral Drugs (4.18) Why Are Drugs so Expensive? (7.0) Lead Compounds for the Development of Drugs (10.9) Aspirin, NSAIDs, and COX-2 Inhibitors (15.9) Penicillins in Clinical Use (15.12) Serendipity in Drug Development (16.8) Semisynthetic Drugs (16.14) Drug Safety (18.19) Searching for Drugs: An Antihistamine, a Nonsedating Antihistamine, and a Drug for Ulcers (19.7) A Peptide Antibiotic (21.2) Natural Products That Modify DNA (26.6) Using Genetic Engineering to Treat the Ebola Virus (26.13) Nanocontainers (27.9) Historical Connections Kekule’s Dream (8.1) Mustard Gas–A Chemical Warfare Agent (10.11) Grubbs, Schrock, Suzuki, and Heck Receive the Nobel Prize (11.5) The Nobel Prize (11.5) Why Radicals No Longer Have to Be Called Free Radicals (12.2) Nikola Tesla (1856–1943) (14.1) The Discovery of Penicillin (15.12) Discovery of the First Antibiotic (18.19) Vitamin C (20.17) Vitamin B1 (23.0) Niacin Deficiency (23.1) The First Antibiotics (23.7) The Structure of DNA: Watson, Crick, Franklin, and Wilkins (26.1) Influenza Pandemics (26.11) Nutritional Connections Trans Fats (5.9) Decaffeinated Coffee and the Cancer Scare (12.11) Food Preservatives (12.11) Is Chocolate a Health Food? (12.11) Nitrosamines and Cancer (18.20) Lactose Intolerance (20.15) Acceptable Daily Intake (20.19) Proteins and Nutrition (21.1) Too Much Broccoli (23.8) Differences in Metabolism (24.0) Fats Versus Carbohydrates as a Source of Energy (24.6) Basal Metabolic Rate (24.10) Omega Fatty Acids (25.1) Olestra: Nonfat with Flavor (25.3) Melamine Poisoning (27.12) The Sunshine Vitamin (28.6) Animals, Birds, Fish—And Vitamin D (28.6) Industrial Connections How is the Octane Number of Gasoline Determined? (3.2) Organic Compounds That Conduct Electricity (8.7) Synthetic Polymers (15.13) The Synthesis of Aspirin (17.7) Teflon: An Accidental Discovery (27.3) Designing a Polymer (27.11) Environmental Connections Pheromones (5.0) Which are More Harmful: Natural Pesticides or Synthetic Pesticides? (6.16) Green Chemistry: Aiming for Sustainability (7.12) The Birth of the Environmental Movement (9.0) Environmental Adaptation (9.14) Benzo[a]pyrene and Cancer (10.8) Chimney Sweeps and Cancer (10.8) Resisting Herbicides (26.13) Recycling Symbols (27.3) General Connections A Few Words About Curved Arrows (5.5) Grain Alcohol and Wood Alcohol (10.1) Blood Alcohol Concentration (10.5) Natural Gas and Petroleum (12.1) Fossil Fuels: A Problematic Energy Source (12.1) Mass Spectrometry in Forensics (13.8) The Originator of Hooke’s Law (13.13) Ultraviolet Light and Sunscreens (13.19) Structural Databases (14.24) What Drug-Enforcement Dogs Are Really Detecting (15.16) Butanedione: An Unpleasant Compound (16.1) Measuring Toxicity (18.0) The Toxicity of Benzene (18.1) Glucose/Dextrose (20.9) Water Softeners: Examples of Cation-Exchange Chromatography (21.5) Curing a Hangover with Vitamin B1 (23.3)

viii Contents PART ONE An Introduction to the Study of Organic Chemistry 1 1 Remembering General Chemistry: Electronic Structure and Bonding 2 CHEMICAL CONNECTION: Natural versus Synthetic Organic Compounds 3 1.1 The Structure of an Atom 4 1.2 How the Electrons in an Atom are Distributed 5 1.3 Covalent Bonds 7 1.4 How the Structure of a Compound is Represented 13 PROBLEM-SOLVING STRATEGY 15 1.5 Atomic Orbitals 19 1.6 An Introduction to Molecular Orbital Theory 21 1.7 How Single Bonds are Formed in Organic Compounds 25 1.8 How a Double Bond is Formed: The Bonds in Ethene 29 CHEMICAL CONNECTION: Diamond, Graphite, Graphene, and Fullerenes: Substances that Contain Only Carbon Atoms 31 1.9 How a Triple Bond is Formed: The Bonds in Ethyne 31 1.10 The Bonds in the Methyl Cation, the Methyl Radical, and the Methyl Anion 33 1.11 The Bonds in Ammonia and in the Ammonium Ion 35 1.12 The Bonds in Water 36 CHEMICAL CONNECTION: Water—A Unique Compound 37 1.13 The Bond in a Hydrogen Halide 38 1.14 Hybridization and Molecular Geometry 39 PROBLEM-SOLVING STRATEGY 39 1.15 Summary: Hybridization, Bond Lengths, Bond Strengths, and Bond Angles 40 PROBLEM-SOLVING STRATEGY 44 1.16 Dipole Moments of Molecules 44 ESSENTIAL CONCEPTS 46 ■ PROBLEMS 47 2 Acids and Bases: Central to Understanding Organic Chemistry 50 2.1 An Introduction to Acids and Bases 50 2.2 pKa and pH 52 PROBLEM-SOLVING STRATEGY 54 CHEMICAL CONNECTION: Acid Rain 54 2.3 Organic Acids and Bases 55 BIOLOGICAL CONNECTION: Poisonous Amines 56 PROBLEM-SOLVING STRATEGY 58 2.4 How to Predict the Outcome of an Acid-Base Reaction 58 2.5 How to Determine the Position of Equilibrium 59 2.6 How the Structure of an Acid Affects its pKa Value 60 2.7 How Substituents Affect the Strength of an Acid 64 PROBLEM-SOLVING STRATEGY 64 2.8 An Introduction to Delocalized Electrons 66 MEDICAL CONNECTION: Fosamax Prevents Bones from Being Nibbled Away 67 PROBLEM-SOLVING STRATEGY 68 2.9 A Summary of the Factors that Determine Acid Strength 69 2.10 How pH Affects the Structure of an Organic Compound 70 PROBLEM-SOLVING STRATEGY 71 CHEMICAL CONNECTION: Derivation of the Henderson-Hasselbalch Equation 72 MEDICAL CONNECTION: Aspirin Must Be in its Basic Form to be Physiologically Active 74 2.11 Buffer Solutions 74 MEDICAL CONNECTION: Blood: A Buffered Solution 75 2.12 Lewis Acids and Bases 76 ESSENTIAL CONCEPTS 77 ■ PROBLEMS 77 TUTORIAL Acids and Bases 80 for Organic Chemistry MasteringChemistry tutorials guide you through the toughest topics in chemistry with self-paced tutorials that provide individualized coaching. These assignable, in-depth tutorials are designed to coach you with hints and feedback specific to your individual misconceptions. For additional practice on Acids and Bases, go to MasteringChemistry, where the following tutorials are available: • Acids and Bases: Definitions • Acids and Bases: Factors That Influence Acid Strength • Acids and Bases: Base Strength and the Effect of pH on Structure • Acids and Bases: Predicting the Position of Equilibrium

3 An Introduction to Organic Compounds: Nomenclature, Physical Properties, and Structure 88 3.1 Alkyl Groups 92 3.2 The Nomenclature of Alkanes 95 INDUSTRIAL CONNECTION: How is the Octane Number of Gasoline Determined? 98 3.3 The Nomenclature of Cycloalkanes 99 PROBLEM-SOLVING STRATEGY 101 3.4 The Nomenclature of Alkyl Halides 101 3.5 The Nomenclature of Ethers 103 3.6 The Nomenclature of Alcohols 104 3.7 The Nomenclature of Amines 106 CHEMICAL CONNECTION: Bad-Smelling Compounds 109 3.8 The Structures of Alkyl Halides, Alcohols, Ethers, and Amines 109 3.9 Noncovalent Interactions 110 PROBLEM-SOLVING STRATEGY 114 MEDICAL CONNECTION: Drugs Bind to Their Receptors 114 3.10 The Solubility of Organic Compounds 116 BIOLOGICAL CONNECTION: Cell Membranes 118 3.11 Rotation Occurs about Carbon–Carbon Single Bonds 118 3.12 Some Cycloalkanes Have Angle Strain 122 CHEMICAL CONNECTION: Von Baeyer, Barbituric Acid, and Blue Jeans 123 PROBLEM-SOLVING STRATEGY 123 3.13 Conformers of Cyclohexane 124 3.14 Conformers of Monosubstituted Cyclohexanes 127 CHEMICAL CONNECTION: Starch and Cellulose—Axial and Equatorial 128 3.15 Conformers of Disubstituted Cyclohexanes 129 PROBLEM-SOLVING STRATEGY 130 PROBLEM-SOLVING STRATEGY 132 3.16 Fused Cyclohexane Rings 134 MEDICAL CONNECTION: Cholesterol and Heart Disease 134 MEDICAL CONNECTION: How High Cholesterol is Treated Clinically 135 ESSENTIAL CONCEPTS 135 ■ PROBLEMS 136 PART TWO Electrophilic Addition Reactions, Stereochemistry, and Electron Delocalization 141 TUTORIAL Using Molecular Models 142 4 Isomers: The Arrangement of Atoms in Space 143 4.1 Cis–Trans Isomers Result from Restricted Rotation 145 CHEMICAL CONNECTION: Cis-Trans Interconversion in Vision 147 4.2 Using the E,Z System to Distinguish Isomers 147 PROBLEM-SOLVING STRATEGY 150 4.3 A Chiral Object Has a Nonsuperimposable Mirror Image 150 4.4 An Asymmetric Center is a Cause of Chirality in a Molecule 151 4.5 Isomers with One Asymmetric Center 152 4.6 Asymmetric Centers and Stereocenters 153 4.7 How to Draw Enantiomers 153 4.8 Naming Enantiomers by the R,S System 154 PROBLEM-SOLVING STRATEGY 157 PROBLEM-SOLVING STRATEGY 158 4.9 Chiral Compounds Are Optically Active 159 4.10 How Specific Rotation Is Measured 161 4.11 Enantiomeric Excess 163 4.12 Compounds with More than One Asymmetric Center 164 4.13 Stereoisomers of Cyclic Compounds 166 PROBLEM-SOLVING STRATEGY 168 4.14 Meso Compounds Have Asymmetric Centers but Are Optically Inactive 169 PROBLEM-SOLVING STRATEGY 171 Using the E,Z system to name alkenes was moved to Chapter 4, so now it appears immediately after using cis and trans to distinguish alkene stereoisomers. for Organic Chemistry MasteringChemistry tutorials guide you through the toughest topics in chemistry with self-paced tutorials that provide individualized coaching. These assignable, in-depth tutorials are designed to coach you with hints and feedback specific to your individual misconceptions. For additional practice on Interconverting Structural Representations, go to MasteringChemistry where the following tutorials are available: • Interconverting Fischer Projections and Perspective Formulas • Interconverting Perspective Formulas, Fischer Projections, and Skeletal Structures • Interconverting Perspective Formulas, Fischer Projections, and Newman Projections for Organic Chemistry Mastering Chemistry tutorials guide you through the toughest topics in chemistry with self-paced tutorials that provide individualized coaching. These assignable, in-depth tutorials are designed to coach you with hints and feedback specific to your individual misconceptions. For additional practice on Molecular Models, go to MasteringChemistry where the following tutorials are available: • Basics of Model Building • Building and Recognizing Chiral Molecules • Recognizing Chirality in Cyclic Molecules

Catalytic hydrogenation and relative stabilities of alkenes were moved from Chapter 6 to Chapter 5 (thermodynamics), so they can be used to illustrate how ΔH° values can be used to determine relative stabilities. x All the reactions in Chapter 6 follow the same mechanism the first step is always addition of the electrophile to the sp2 carbon bonded to the most hydrogens. for Organic Chemistry MasteringChemistry tutorials guide you through the toughest topics in chemistry with self-paced tutorials that provide individualized coaching. These assignable, in-depth tutorials are designed to coach you with hints and feedback specific to your individual misconceptions. For additional practice on Drawing Curved Arrows: Pushing Electrons, go to MasteringChemistry where the following tutorials are available: • An Exercise in Drawing Curved Arrows: Pushing Electrons • An Exercise in Drawing Curved Arrows: Predicting Electron Movement • An Exercise in Drawing Curved Arrows: Interpreting Electron Movement 4.15 How to Name Isomers with More than One Asymmetric Center 172 PROBLEM-SOLVING STRATEGY 175 4.16 Nitrogen and Phosphorus Atoms Can Be Asymmetric Centers 177 4.17 Receptors 178 MEDICAL CONNECTION: The Enantiomers of Thalidomide 179 4.18 How Enantiomers Can Be Separated 179 PHARMACEUTICAL CONNECTION: Chiral Drugs 180 ESSENTIAL CONCEPTS 181 ■ PROBLEMS 181 TUTORIAL Interconverting Structural Representations 187 5 Alkenes: Structure, Nomenclature, and an Introduction to Reactivity • Thermodynamics and Kinetics 190 ENVIRONMENTAL CONNECTION: Pheromones 191 5.1 Molecular Formulas and the Degree of Unsaturation 191 5.2 The Nomenclature of Alkenes 192 5.3 The Structure of Alkenes 195 PROBLEM-SOLVING STRATEGY 196 5.4 How An Organic Compound Reacts Depends on Its Functional Group 197 5.5 How Alkenes React • Curved Arrows Show the Flow of Electrons 198 GENERAL CONNECTION: A Few Words About Curved Arrows 200 5.6 Thermodynamics: How Much Product is Formed? 202 5.7 Increasing the Amount of Product Formed in a Reaction 205 5.8 Calculating ∆H° Values 206 5.9 Using ∆H° Values to Determine the Relative Stabilities of Alkenes 207 PROBLEM-SOLVING STRATEGY 208 NUTRITIONAL CONNECTION: Trans Fats 211 5.10 Kinetics: How Fast is the Product Formed? 211 5.11 The Rate of a Chemical Reaction 213 CHEMICAL CONNECTION: The Difference between ∆G‡ and Ea 215 5.12 A Reaction Coordinate Diagram Describes the Energy Changes That Take Place During a Reaction 215 5.13 Catalysis 218 5.14 Catalysis by Enzymes 219 ESSENTIAL CONCEPTS 220 ■ PROBLEMS 221 CHEMICAL CONNECTION: Calculating Kinetic Parameters 224 TUTORIAL Drawing Curved Arrows 225 6 The Reactions of Alkenes • The Stereochemistry of Addition Reactions 235 6.1 The Addition of a Hydrogen Halide to an Alkene 236 6.2 Carbocation Stability Depends on the Number of Alkyl Groups Attached to the Positively Charged Carbon 237 6.3 What Does the Structure of the Transition State Look Like? 239 6.4 Electrophilic Addition Reactions Are Regioselective 241 PROBLEM-SOLVING STRATEGY 243 6.5 The Addition of Water to an Alkene 245 6.6 The Addition of an Alcohol to an Alkene 246 6.7 A Carbocation Will Rearrange if It Can Form a More Stable Carbocation 248 6.8 The Addition of Borane to an Alkene: Hydroboration–Oxidation 250 CHEMICAL CONNECTION: Borane and Diborane 251 6.9 The Addition of a Halogen to an Alkene 254 PROBLEM-SOLVING STRATEGY 257 6.10 The Addition of a Peroxyacid to an Alkene 257 6.11 The Addition of Ozone to an Alkene: Ozonolysis 259 PROBLEM-SOLVING STRATEGY 261 6.12 Regioselective, Stereoselective, And Stereospecific Reactions 263 6.13 The Stereochemistry of Electrophilic Addition Reactions 264 CHEMICAL CONNECTION: Cyclic Alkenes 269 PROBLEM-SOLVING STRATEGY 274 6.14 The Stereochemistry of Enzyme-Catalyzed Reactions 276

xi 6.15 Enantiomers Can Be Distinguished by Biological Molecules 277 CHEMICAL CONNECTION: Chiral Catalysts 278 6.16 Reactions and Synthesis 278 ENVIRONMENTAL CONNECTION: Which are More Harmful: Natural Pesticides or Synthetic Pesticides? 280 ESSENTIAL CONCEPTS 280 ■ SUMMARY OF REACTIONS 281 ■ PROBLEMS 282 7 The Reactions of Alkynes • An Introduction to Multistep Synthesis 288 MEDICAL CONNECTION: Synthetic Alkynes Are Used to Treat Parkinson’s Disease 289 PHARMACEUTICAL CONNECTION: Why Are Drugs so Expensive? 290 7.1 The Nomenclature of Alkynes 290 MEDICAL CONNECTION: Synthetic Alkynes Are Used for Birth Control 291 7.2 How to Name a Compound That Has More than One Functional Group 292 7.3 The Structure of Alkynes 293 BIOLOGICAL CONNECTION: How a Banana Slug Knows What to Eat 293 7.4 The Physical Properties of Unsaturated Hydrocarbons 294 7.5 The Reactivity of Alkynes 295 7.6 The Addition of Hydrogen Halides and the Addition of Halogens to an Alkyne 296 7.7 The Addition of Water to an Alkyne 299 7.8 The Addition of Borane to an Alkyne: Hydroboration–Oxidation 301 7.9 The Addition of Hydrogen to an Alkyne 302 7.10 A Hydrogen Bonded to an sp Carbon Is “Acidic” 304 CHEMICAL CONNECTION: Sodium Amide and Sodium in Ammonia 305 PROBLEM-SOLVING STRATEGY 305 7.11 Synthesis Using Acetylide Ions 306 7.12 DESIGNING A SYNTHESIS I: An Introduction to Multistep Synthesis 307 ENVIRONMENTAL CONNECTION: Green Chemistry: Aiming for Sustainability 312 ESSENTIAL CONCEPTS 312 ■ SUMMARY OF REACTIONS 313 ■ PROBLEMS 314 8 Delocalized Electrons: Their Effect on Stability, pKa, and the Products of a Reaction • Aromaticity and Electronic Effects: An Introduction to the Reactions of Benzene 318 8.1 Delocalized Electrons Explain Benzene’s Structure 319 HISTORICAL CONNECTION: Kekule’s Dream 321 8.2 The Bonding in Benzene 321 8.3 Resonance Contributors and the Resonance Hybrid 322 8.4 How to Draw Resonance Contributors 323 BIOLOGICAL CONNECTION: Electron Delocalization Affects the Three-Dimensional Shape of Proteins 326 8.5 The Predicted Stabilities of Resonance Contributors 326 PROBLEM-SOLVING STRATEGY 328 8.6 Delocalization Energy is the Additional Stability Delocalized Electrons Give to a Compound 329 8.7 Delocalized Electrons Increase Stability 330 INDUSTRIAL CONNECTION: Organic Compounds That Conduct Electricity 333 8.8 A Molecular Orbital Description of Stability 335 8.9 Delocalized Electrons Affect pKa Values 339 PROBLEM-SOLVING STRATEGY 342 8.10 Electronic Effects 342 8.11 Delocalized Electrons Can Affect the Product of a Reaction 346 8.12 Reactions of Dienes 347 8.13 Thermodynamic Versus Kinetic Control 350 8.14 The Diels–Alder Reaction is a 1,4-Addition Reaction 355 8.15 Retrosynthetic Analysis of the Diels–Alder Reaction 361 8.16 Benzene is an Aromatic Compound 362 8.17 The Two Criteria for Aromaticity 363 8.18 Applying the Criteria for Aromaticity 364 CHEMICAL CONNECTION: Buckyballs 365 PROBLEM-SOLVING STRATEGY 366 8.19 A Molecular Orbital Description of Aromaticity 367 Chapter 8 starts by discussing the structure of benzene because it is the ideal compound to use to explain delocalized electrons. This chapter also includes a discussion of aromaticity, so a short introduction to electrophilic aromatic substitution reactions is now included. This allows students to see how aromaticity causes benzene to undergo electrophilic substitution rather than electrophilic addition— the reactions they have just finished studying. Traditionally, electronic effects are taught so students can understand the directing effects of substituents on benzene rings. Now that most of the chemistry of benzene follows carbonyl chemistry, students need to know about electronic effects before they get to benzene chemistry (so they are better prepared for spectroscopy and carbonyl chemistry). Therefore, electronic effects are now discussed in Chapter 8 and used to teach students how substituents affect the pKa values of phenols, benzoic acids, and anilinium ions. Electronic effects are then reviewed in the chapter on benzene. for Organic Chemistry MasteringChemistry tutorials guide you through the toughest topics in chemistry with self-paced tutorials that provide individualized coaching. These assignable, in-depth tutorials are designed to coach you with hints and feedback specific to your individual misconceptions. For additional practice on Drawing Resonance Contributors, go to MasteringChemistry where the following tutorials are available: • Drawing Resonance Contributors: Moving p Electrons • Drawing Resonance Contributors: Predicting Aromaticity • Drawing Resonance Contributors: Substituted Benzene Rings