CHAPTER 01 Lewis Structure, Resonance and Functional groups 1.1 Lewis Structure and Formal Charge ... 2 1.1.1 How many Bonds are needed? ... 2 1.1.2 Index of Hydrogen Deficiency ... 3 1.1.3 Drawing Lewis Structure ... 4 1.1.4 Formal Charge ... 6 1.1.5 Octet Rule Does not Apply to Some Elements ... 9 1.1.6 Drawing Skeletal Lewis Structures ... 11 1.1.7 Don't Make errors in Drawing Lewis Structure ... 13 1.2 Resonance Structure ... 15 1.2.1 Drawing Resonance Structures ... 16 1.2.2 Resonance is Possible in Three Different Cases ... 17 1.2.3 Rules in Drawing Resonance Structures ... 21 1.2.4 Resonance Hybrid ... 25 1.2.5 Stabilization by Resonance ... 29 1.3 Organic Functional Groups ... 32 1.3.1 The Structure and Naming of Functional Groups ... 32 1.3.2 Same Functional Group May Differ in Reactivity ... 35 CHAPTER 02 Orbital Interactions and Bond Formation 2.1 Atomic Orbitals ... 40 2.2 δ-interaction and δ-Bond Formation ... 43 2.3 π-interaction and π-Bond Formation ... 45 2.4 Energetics of Orbital Interaction ... 46 2.5 Stability of Bonds and Orbital Overlap ... 49 2.6 Orbital Hybridization ... 51 2.7 δ-Bond-Formation Using Hybrid Orbitals ... 53 2.8 Carbon-Carbon(Heteroatom) π-Bond Formation ... 54 2.9 More Efficient Overlap with Hybrid Orbitals ... 56 2.10 Moreπ-Systems(Extended π-System): Allylic System ... 59 2.11 Conjugate π-System: 1, 3-Butadience and Enones ... 62 2.12 Cyclic Conjugated System and Aromaticity ... 67 2.13 Huckel's Rule and Aromaticity ... 70 2.14 Polycyclic and Heterocycilc Aromatics ... 72 2.15 Orbitals and Bond Formation between Molecules ... 75 2.16 Orbital Change in Bond Formation ... 79 2.17 Orbital Interaction within a Molecule ... 82 2.18 Stereoelectronic Effect ... 85 CHAPTER 03 Bronsted Acids and Bases: Proton transfer 3.1 Bronsted Acids and Base ... 90 3.2 Bronsted Acids Base Reactions(Proton Transfer) ... 91 3.3 The Strength of Bronsted Acids: pKa ... 93 3.4 How to Predict AcidㆍBase Equilibria ... 96 3.5 Factors Affecting Acid Strength ... 99 3.5.1 Element Effect ... 99 3.5.2 Hybridization Effect ... 102 3.5.3 Resonance Effect ... 104 3.5.4 Inductive Effect ... 106 3.6 Summary of factors Determing Acid Strength ... 109 3.7 Solvent Effect on the Acidity ... 111 3.8 Basicity of Bronsted Base ... 114 3.9 Rate of Proton Transfer ... 117 3.10 Tautomerization: An Example of Acid-Base Reactions ... 120 CHAPTER 04 Lewis Acids and Bases : Nucleophiles and Electrophiles 4.1 Lewis Acids and Bases: Nucleophiles and Electrophiles ... 130 4.2 Polar Organic Reactions ... 131 4.3 Types of Nucleophiles in Organic Reactions ... 134 4.4 The Reactivity of Nucleophiles: Nucleophilicity ... 136 4.5 Types of Electrophiles Used in Organic Reactions ... 140 4.6 Reactivity of Electrophiles ... 142 4.7 Good Nucleofugal Leaving Groups ... 144 4.8 How to Find Nucleophilic and Electrophilic Sites in a Compound ... 146 4.9 What are Hard and Soft Acids and Bases ... 150 4.10 Classification of Hard and Soft Acids and Bases ... 153 4.11 Frontier Orbital Theory: Core of HSAB ... 155 4.12 HSAB Principle: Key to Understand Obscure Reactivity ... 157 4.13 HSAB Theory is not 'one and only' Solution ... 163 CHAPTER 05 Configuration and Conformation 5.1 Drawing Stereo Molecules ... 168 5.2 Matter of Configuration and Conformation ... 169 5.3 Priority of Substituents: Cahn-Ingold-Prelog Convention ... 171 5.4 Naming Geometrical Isomers ... 172 5.5 Naming Configuration of Chiral Compounds ... 175 5.6 Inversion and Retention of Configuration in Organic Reactions ... 179 5.7 Prochirality ... 180 5.8 Stereospecificity and Stereoselectivity ... 182 5.9 Conformation of Open Chain Hydrocarbons ... 186 5.9.1 Conformation of Ethane ... 187 5.9.2 Conformation of Propane ... 188 5.9.3 Conformation of Butane ... 189 5.10 Conformation of Unsaturated System ... 191 5.11 Conformation of Cyclic Compounds ... 194 5.11.1 Strains in cyclic Compounds ... 194 5.11.2 Angel strain ... 195 5.11.3 Tortional strain ... 196 5.11.4 Conformation of Cyclohexane ... 197 5.11.5 Conformation of Substituted Cyclohexane ... 199 5.11.6 Conformation of fused Bicyclics ... 202 5.11.7 Conformation of Cyclohexene and Methylenecyclohexane ... 203 5.12 Conformation Changes Many Features of Organic Reactions ... 205 CHAPTER 06 Why and How Reactions Occur? 6.1 Bonding Characteristics-Bond Strength and Bond Polarity ... 212 6.1.1 Bond Strength ... 212 6.1.2 Bond Polarity ... 215 6.2 Bond Cleavage ... 217 6.3 Process of Bond Formation ... 219 6.4 Reaction Energy Profiles(Potential Energy Diagram) ... 222 6.5 Free Energy and Chemical Equilibrium ... 225 6.6 reaction Kinetics and Transition State ... 228 6.7 Transition State Characters and Hammond Postulate ... 231 6.8 Thermodynamic versus Kinetic Control ... 239 6.9 Effects of Thermodynamics on Chemical Reactions ... 244 6.9.1 Effect of Ring Strain ... 244 6.9.2 Aromatic stability ... 246 6.9.3 Effect of Entropies ... 248 6.9.4 Effect of Bond Strength ... 250 6.10 Effects of Kinetics on Chemical reactions ... 252 6.10.1 Electronic Effects ... 254 6.10.2 Effect of Entropy of Activation ... 256 6.10.3 Steric Effects ... 260 6.10.4 Orbital Overlap＆Stereoelectronic Effect ... 263 6.11 Combined Effects of Thermodynamics and Kinetics ... 267 CHAPTER 07 How to Draw Reaction Mechanisms 7.1 How Organic Reactions are Written? ... 272 7.2 Recognizing Bonds Broken and Formed by Numbering ... 276 7.3 Electron Source and Electron Sink ... 279 7.4 Arrows from Electron Source to Electron Sink ... 283 7.5 Don't Make Trivial Errors ... 289 7.5.1 Octet Rule: A Must under Any circumstances ... 289 7.5.2 Formal Charges Cannot be Omitted ... 290 7.5.3 From Electron Source and Electron Sink ... 290 7.5.4 Don't Let Protons Fly Away ... 292 7.5.5 A Strong Acid and Strong Base Cannot Exist Together ... 292 7.5.6 Too Many Arrows Spoil the Mechanism ... 294 7.6 Tips for Drawing Better Mechanism ... 296 7.6.1 The Simpler, the Better〈Occam's Razor〉 ... 296 7.6.2 All the Given Information Have to be Considered ... 297 7.6.3 Avoid Termolecular Mechanism ... 299 7.6.4 Avoid Intermediates of Too High Energy ... 301 7.6.5 six-Membered Cyclic TS can be a Better Choice ... 303 7.6.6 Four-Membered Cyclic TS is Seldom a Good Choice ... 306 7.6.7 π-Nucleophile과 Lone Pair Nucleophile ... 308 7.6.8 One-Step Substitution is NOT Possible at sp² Carbon ... 310 7.7 Drawing more reasonable Mechanism ... 312 7.8 There are Mechanisms and There are Mechanisms ... 315 CHAPTER 08 Classification of Organic Reactions 8.1 Classification by Overall Transformation ... 324 8.1.1 Additions Reactions ... 324 8.1.2 Elimination Reactions(β-Elimination) ... 327 8.1.3 Substitution Reactions ... 330 8.1.4 Rearrangements ... 336 8.2 One-Step Concerted Reactions ... 341 8.2.1 Polar Concerted Reactions ... 342 8.2.2 Pericyclic reactions ... 344 8.2.3 Classification of Pericyclic Reactions ... 345 8.2.4 Cycloaddition(Diels-Alder 반응) ... 347 8.2.5 Electrocyclization ... 347 8.2.6 Sigmatropic rearrangements ... 348 8.2.7 Ene Reaction ... 349 8.2.8 Tips for Recognizing Pericyclic Reactions ... 350 8.3 Reactive IntermediateⅠ: Radicals ... 352 8.3.1 Reactions Involving Radical Intermediates ... 352 8.3.2 Radical Generation: Homolysis of Spin-Paired Molecules ... 353 8.3.3 Type of Reactions Radicals Undergo ... 354 8.3.4 Radical chain Reactions ... 355 8.3.5 How to Recognize Radical Reactions ... 358 8.4 Reactive Intermediate Ⅱ: Carbocations ... 359 8.4.1 Very Unstable Carbocation Intermediates ... 359 8.4.2 Generation of Carbocations: Role of Proton and Lewis Acids ... 362 8.4.3 Typical Carbocation Rearrangements ... 363 8.4.4 Types of Reactions of Carbocations ... 366 8.5 Reactive Intermediate Ⅲ: Carbanions ... 367 8.5.1 Stability of Carbanions: Role of Metal Counterion ... 367 8.5.2 Methods of Carbanion Generation ... 368 8.5.3 Carbanions React with Electrophiles ... 371 8.6 Reactive Intermediate Ⅳ: Carbenes ... 372 8.6.1 Generation of Carbenes ... 372 8.6.2 Reactions of Carbenes ... 374 8.7 Oxidation and Reduction of Organic Functional Groups ... 377 8.7.1 Counting Oxidation Number in a Compound ... 377 8.7.2 Reductive and Oxidative Reactions ... 379 8.7.3 Common Reducing Agents ... 381 8.7.4 Reduction of Organic Functional Groups ... 382 8.7.5 Common Oxidizing Agents ... 387 8.7.6 Oxidation of Functional Groups ... 388