CONTENTS Introduction iii CHAPTER 1 BOND-LINE DRAWINGS 1 1.1 How to Read Bond-Line Drawings 1 1.2 How to Draw Bond-Line Drawings 1.3 Mistakes to Avoid7 1.4 More Exercises 8 1.5 Identifying Formal Charges 10 1.6 Finding Lone Pairs That Are Not Drawn 14 CHAPTER 2 RESONANCE 20 2.1 What Is Resonance?20 2.4 Drawing Good Arrows 27 2.5 Formal Charges in Resonance Structures 29 2.6 Drawing Resonance Structures-Step by Step 33 2.7 Drawing Resonance Structures-By Recognizing Patterns 38 one Pair Next to a Pi Bond 38 A Lone Pair Next to a Positive Charge 41 A Pi Bond Next to a Positive Charge 43 A Pi Bond Between Two Atoms,Where One of Those Atoms Is Electronegative (N.O.etc.)44 Pi Bonds Go ng All the Way Around a Ring 45 2.8 Ass essing the Relative Importance of Resonance Structures 47 CHAPTER 3 ACID-BASE REACTIONS 53 3.1 Factor 1-What Atom Is the Charge on?54 3.2 Factor 2 -Resonance 57 3.3 Factor 3-Induction 62 34 Factor 4-Orbitals 66 3.5 Ranking the Four Factors 67 3.6 Quan easureme avalues)71 3.7 Predicting the Postion of Equilibrium7 3.8 Showing a Mechanism 73
Introduction iii CHAPTER 1 BOND-LINE DRAWINGS 1 1.1 How to Read Bond-Line Drawings 1 1.2How to Draw Bond-Line Drawings 5 1.3 Mistakes to Avoid 7 1.4 More Exercises 8 1.5 Identifying Formal Charges 10 1.6 Finding Lone Pairs That Are Not Drawn 14 CHAPTER 2 RESONANCE 20 2.1 What Is Resonance? 20 2.2 Curved Arrows: The Tools for Drawing Resonance Structures 21 2.3 The Two Commandments 24 2.4 Drawing Good Arrows 27 2.5 Formal Charges in Resonance Structures 29 2.6 Drawing Resonance Structures—Step by Step 33 2.7 Drawing Resonance Structures—By Recognizing Patterns 38 A Lone Pair Next to a Pi Bond 38 A Lone Pair Next to a Positive Charge 41 A Pi Bond Next to a Positive Charge 43 A Pi Bond Between Two Atoms, Where One of Those Atoms Is Electronegative (N, O, etc.) 44 Pi Bonds Going All the Way Around a Ring 45 2.8 Assessing the Relative Importance of Resonance Structures 47 CHAPTER 3 ACID–BASE REACTIONS 53 3.1 Factor 1—What Atom Is the Charge on? 54 3.2Factor 2—Resonance 57 3.3 Factor 3—Induction 62 3.4 Factor 4—Orbitals 66 3.5 Ranking the Four Factors 67 3.6 Quantitative Measurement (pKa values) 71 3.7 Predicting the Position of Equilibrium 71 3.8 Showing a Mechanism 73 ix CONTENTS 6753_Klein_00.qxd 5/1/07 5:02 PM Page ix
X CONTENTS CHAPTER 4 GEOMETRY 76 4.1 Orbitals and Hybridization States 76 4.2 Geometry 80 CHAPTER 5 NOMENCLATURE 84 5.1 Functional Group 85 5.2 Unsaturation 5.3 Naming the Parent Chain 89 5.4 Naming Substituents 91 5.5 Stereoisomerism 95 5.7 Comn 103 5.8 Going from a Name to a Structure 104 CHAPTER 6 CONFORMATIONS 106 6.1 How to Draw a Newman Projection 107 6.2 Ranking the Stability of Newman Projections 111 6.3 Drawing Chair Conformations 115 6.4 Placing Groups on the Chair 118 6.5 Ring Flipping 123 6.6 Com 129 133 CHAPTER 7 CONFIGURATIONS 134 7.1 Locating Stereocenters 135 7.2 Determining the Configuration of a Stereocenter 138 7.3 Nomenclature 146 7.4 Drawing Enantiomers 151 75 Diastereomers 156 7.6 Meso Co unds 157 7.8 Optical Activity 165 CHAPTER 8 MECHANISMS 167 8.1 Curved Arrows 168 8.2 Arrow Pushing 173 8.3 Drawing Intermediates 175 8.4 Nucleophiles and Electrophiles 178 8.5 Bases Versus Nucleophiles 179 8.6 The Regiochemistry Is Contained Within the Mechanism 182
CHAPTER 4 GEOMETRY 76 4.1 Orbitals and Hybridization States 76 4.2Geometry 80 CHAPTER 5 NOMENCLATURE 84 5.1 Functional Group 85 5.2Unsaturation 87 5.3 Naming the Parent Chain 89 5.4 Naming Substituents 91 5.5 Stereoisomerism 95 5.6 Numbering 98 5.7 Common Names 103 5.8 Going from a Name to a Structure 104 CHAPTER 6 CONFORMATIONS 106 6.1 How to Draw a Newman Projection 107 6.2Ranking the Stability of Newman Projections 111 6.3 Drawing Chair Conformations 115 6.4 Placing Groups on the Chair 118 6.5 Ring Flipping 123 6.6 Comparing the Stability of Chairs 129 6.7 Don’t Be Confused by the Nomenclature 133 CHAPTER 7 CONFIGURATIONS 134 7.1 Locating Stereocenters 135 7.2Determining the Configuration of a Stereocenter 138 7.3 Nomenclature 146 7.4 Drawing Enantiomers 151 7.5 Diastereomers 156 7.6 Meso Compounds 157 7.7 Drawing Fischer Projections 160 7.8 Optical Activity 165 CHAPTER 8 MECHANISMS 167 8.1 Curved Arrows 168 8.2Arrow Pushing 173 8.3 Drawing Intermediates 175 8.4 Nucleophiles and Electrophiles 178 8.5 Bases Versus Nucleophiles 179 8.6 The Regiochemistry Is Contained Within the Mechanism 182 x CONTENTS 6753_Klein_00.qxd 5/1/07 5:02 PM Page x
CONTENTS xi 8.7 The Stereochemistry Is Contained Within the Mechanism 185 8.8 A List of Mechanisms 190 CHAPTER 9 SUBSTITUTION REACTIONS 211 9.1 The Mechanisms 211 9.2 Factor 1-The Electrophile(Substrate)214 9.3 Factor 2-The Nucleophile 217 9.4 Factor 3-The Leaving Group 220 9.5 Factor 4The Solvent 223 9.6 Using All Four Factors 22 9.7 Substitution Reactions Teach Us Some Important Lessons 227 CHAPTER 10 ELIMINATION REACTIONS 229 10.1 Mechanisms(El and E2)230 10.2 Factor 1-The Substrate 231 103 Factor 2-The Base 232 10.4 Factor3-The Leaving Group 35 10.5 Factor4Solvent Effects 36 10.6 Using All of the Factors 236 10.7 Elimination Reactions-Regiochemistry and Stereochemistry 238 CHAPTER 11 ADDITION REACTIONS 242 11.1 Terminology Describing Regiochemistry 242 y Describing Stereochemistry 11.3 Adding H and H 11.4 Adding H and X,Markovnikov 256 11.5 Adding H and Br,Anti-Markovnikov 263 11.6 Adding H and OH,Markovnikov 268 11.7 Adding H and OH,Anti-Markovnikov 272 11.8 Synthesis Techn ques 277 11Adding Br and Br Adding Br and OH 11.10 Adding OH and OH,Anti 290 11.11 Adding OH and OH,Syn 293 11.12 Oxidative Cleavage of an Alkene 296 CHAPTER 12 PREDICTING PRODUCTS 299 12.1 General Tips for Predicting Products 299 12.2G tting Prac 1ce30 12.3 Substitution Versus Elimination Reactions 311 12.4 Looking Forward 315
8.7 The Stereochemistry Is Contained Within the Mechanism 185 8.8 A List of Mechanisms 190 CHAPTER 9 SUBSTITUTION REACTIONS 211 9.1 The Mechanisms 211 9.2Factor 1—The Electrophile (Substrate) 214 9.3 Factor 2—The Nucleophile 217 9.4 Factor 3—The Leaving Group 220 9.5 Factor 4—The Solvent 223 9.6 Using All Four Factors 226 9.7 Substitution Reactions Teach Us Some Important Lessons 227 CHAPTER 10 ELIMINATION REACTIONS 229 10.1 Mechanisms (E1 and E2) 230 10.2Factor 1—The Substrate 231 10.3 Factor 2—The Base 232 10.4 Factor 3—The Leaving Group 235 10.5 Factor 4—Solvent Effects 236 10.6 Using All of the Factors 236 10.7 Elimination Reactions—Regiochemistry and Stereochemistry 238 CHAPTER 11 ADDITION REACTIONS 242 11.1 Terminology Describing Regiochemistry 242 11.2Terminology Describing Stereochemistry 244 11.3 Adding H and H 253 11.4 Adding H and X, Markovnikov 256 11.5 Adding H and Br, Anti-Markovnikov 263 11.6 Adding H and OH, Markovnikov 268 11.7 Adding H and OH, Anti-Markovnikov 272 11.8 Synthesis Techniques 277 11.9 Adding Br and Br; Adding Br and OH 285 11.10 Adding OH and OH, Anti 290 11.11 Adding OH and OH, Syn 293 11.12Oxidative Cleavage of an Alkene 296 CHAPTER 12 PREDICTING PRODUCTS 299 12.1 General Tips for Predicting Products 299 12.2 Getting Practice 300 12.3 Substitution Versus Elimination Reactions 311 12.4 Looking Forward 315 CONTENTS xi 6753_Klein_00.qxd 5/1/07 5:02 PM Page xi
xii CONTENTS CHAPTER 13 SYNTHESIS 316 13.1 One-step Syntheses 318 13.2 Multistep Syntheses 13.3 Retrosynthetic Analysis 330 13.4 Creating Your Own Problems 331 Answer Key 333 Index 354
CHAPTER 13 SYNTHESIS 316 13.1 One-step Syntheses 318 13.2Multistep Syntheses 329 13.3 Retrosynthetic Analysis 330 13.4 Creating Your Own Problems 331 Answer Key 333 Index 354 xii CONTENTS 6753_Klein_00.qxd 5/1/07 5:02 PM Page xii
CHAPTER BOND-LINE DRAWINGS To do well in organic chemistry.you must first learn to interpret the drawings that you see a drawing of a molecule it is absolutely riti cal that you can read all of the information contained in that drawing.Without this skill,it will be impossible to master even the most basic reactions and concepts. Molecules can be drawn in many ways: HHHH H-CC=C (CH3)2CHCH=CHCOCH3 √0 Without a doubt,the last structure (bond-line drawing)is the quickest to draw.the quickest to read.and the best way to communicate.Open your textbook ond half and ou will find that every e is plastered with neMot studentswl ain a faiiarity w ese drawings over time,not realizing how absolutely critical it is to be able to read these drawings flu- ently.This chapter will help you develop your skills in reading these drawings quickly and fluently. 1.1 HOW TO READ BOND-LINE DRAWINGS Bond-line drawings show the carbon skeleton(the connections of all the carbor atoms that build up the backbone of the molecule) with ny functiona groups that are atta hed.,such asOH orBr Lines are drawn nformar so that the end of every line represents a carbon atom.For example,the following compound has 6 carbon atoms: It is a common mistake to forget that the ends of lines represent carbon atoms as well.For example,the following molecule has six carbon atoms(make sure you can count them):
To do well in organic chemistry, you must first learn to interpret the drawings that organic chemists use. When you see a drawing of a molecule, it is absolutely critical that you can read all of the information contained in that drawing. Without this skill, it will be impossible to master even the most basic reactions and concepts. Molecules can be drawn in many ways: Without a doubt, the last structure (bond-line drawing) is the quickest to draw, the quickest to read, and the best way to communicate. Open your textbook to any page in the second half and you will find that every page is plastered with bond-line drawings. Most students will gain a familiarity with these drawings over time, not realizing how absolutely critical it is to be able to read these drawings fluently. This chapter will help you develop your skills in reading these drawings quickly and fluently. 1.1 HOW TO READ BOND-LINE DRAWINGS Bond-line drawings show the carbon skeleton (the connections of all the carbon atoms that build up the backbone, or skeleton, of the molecule) with any functional groups that are attached, such as – OH or – Br. Lines are drawn in a zigzag format, so that the end of every line represents a carbon atom. For example, the following compound has 6 carbon atoms: It is a common mistake to forget that the ends of lines represent carbon atoms as well. For example, the following molecule has six carbon atoms (make sure you can count them): C C (CH3)2CHCH=CHCOCH3 O H H C C H C HH H H H H C O C H H H 1 CHAPTER1 BOND-LINE DRAWINGS 6753_Klein_01.qxd 5/1/07 5:03 PM Page 1