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OR G A N I C CH E M I S T RY
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OR G A N I C CH E M I S T RY
Second Edition
Thomas N. SorrellThe University of North Carolina at Chapel Hill
University Science BooksSausalito, California
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University Science Books www.uscibooks.com
Developmental editor: Mary CastellionProduction manager: Ann KnightManuscript editor: Jeanette StiefelText design: Caroline McGowanCover design: George KelvinCompositor: Publishers’ Design and Production Services, Inc.Illustrator: LineworksManufacturer: VonHoffman Corporation
This book is printed on acid-free paper.
University Science Books, Sausalito, California©1999, 2006All rights reserved. First edition 1999. Second edition 2006.
ISBN 10: 1-891389-38-6ISBN 13: 978-1-891389-38-2
Reproduction or translation of any part of this work beyond that permitted by Section107 or 108 of the 1976 United States Copyright Act without the permission of thecopyright owner is unlawful. Requests for permission or further information shouldbe addressed to the Permissions Department, University Science Books.
Library of Congress Cataloging-in-Publication Data
Sorrell, Thomas N.Organic Chemistry / Thomas N. Sorrell.—2nd ed.
p. cm.Includes bibliographical reference and index.ISBN 1-891389-38-6 (alk. paper)
1. Chemistry, Organic—Textbooks. I. Title.
QD251.3.S67 2005547—dc22 2005052854
Printed in the United States of America10 9 8 7 6 5 4 3 2 1
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This book is dedicated to Courtney—a loving daughter and burgeoning research chemist,
who perceives the beauty of organic chemistry asreadily as she sees the splendors of the Carolina coast
and the majesty of the Rocky Mountains.
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PREFACE xvii
TO THE STUDENT xix
TO THE INSTRUCTOR xxi
ACKNOWLEDGMENTS xxiii
CONTENTSOVERVIEW
vii
Chapter 1 THE STRUCTURES OF ORGANIC MOLECULES 1
2 BONDING IN ORGANIC MOLECULES 35
3 THE CONFORMATIONS OF ORGANIC MOLECULES 77
4 THE STEREOCHEMISTRY OF ORGANIC MOLECULES 105
5 CHEMICAL REACTIONS AND MECHANISMS 137
6 SUBSTITUTION REACTIONS OF ALKYL HALIDES 177
7 SUBSTITUTION REACTIONS OF ALCOHOLS AND RELATED COMPOUNDS 211
8 ELIMINATION REACTIONS OF ALKYL HALIDES, ALCOHOLS, AND RELATED COMPOUNDS 239
9 ADDITION REACTIONS OF ALKENES AND ALKYNES 267
10 ADDITION REACTIONS OF CONJUGATED DIENES 303
11 OXIDATION AND REDUCTION REACTIONS 331
12 FREE RADICAL REACTIONS 363
13 PROTON AND CARBON NMR SPECTROSCOPY 397
14 DETERMINING THE STRUCTURES OF ORGANIC MOLECULES 445
15 ORGANOMETALLIC REAGENTS AND CHEMICAL SYNTHESIS 487
16 ASYMMETRIC REACTIONS AND SYNTHESIS 525
17 THE CHEMISTRY OF BENZENE AND ITS DERIVATIVES 561
18 NUCLEOPHILIC ADDITION REACTIONS OF ALDEHYDES AND KETONES 605
19 ADDITION–SUBSTITUTION REACTIONS OF ALDEHYDES AND KETONES:CARBOHYDRATE CHEMISTRY 635
20 ADDITION–ELIMINATION REACTIONS OF ALDEHYDES AND KETONES 669
21 ADDITION–ELIMINATION REACTIONS OF CARBOXYLIC ACIDS AND DERIVATIVES 701
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22 THE ACID–BASE CHEMISTRY OF CARBONYL COMPOUNDS 745
23 THE NUCLEOPHILIC ADDITION REACTIONS OF ENOLATE IONS 787
24 CONJUGATE ADDITION REACTIONS OF UNSATURATED CARBONYL COMPOUNDS 823
25 THE CHEMISTRY OF POLYCYCLIC AND HETEROCYCLIC ARENES 859
26 POLYMERS AND POLYMERIZATION 893
27 AMINO ACIDS, PEPTIDES, AND PROTEINS 921
28 NUCLEIC ACIDS AND MOLECULAR RECOGNITION 953
APPENDIX A-1
GLOSSARY G-1
INDEX I-1
viii CONTENTS OVERVIEW
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CONTENTS
ix
PREFACE xii
TO THE STUDENT xix
TO THE INSTRUCTOR xxi
ACKNOWLEDGMENTS xxiii
Chapter 1 THE STRUCTURES OF ORGANIC MOLECULES 1
1.1 STRUCTURAL COMPONENTS OF ORGANIC MOLECULES 2
1.2 STRUCTURAL FORMULAS AND CONDENSED STRUCTURES 3
1.3 SYSTEMATIC NOMENCLATURE: IUPAC NAMES 9
1.4 CONSTITUTIONAL ISOMERS AND HYDROCARBON SUBSTITUENTS 18
1.5 NAMING ORGANIC COMPOUNDS 25
CHAPTER SUMMARY 29
Chapter 2 BONDING IN ORGANIC MOLECULES 35
2.1 LEWIS STRUCTURES 35
2.2 BOND PROPERTIES 40
2.3 RESONANCE STRUCTURES 43
2.4 THE FORMATION OF BONDS 49
2.5 HYBRID ORBITALS AND SHAPES OF MOLECULES 51
2.6 BONUS WITH HERTEROATOMS 60
2.7 DELOCALIZED π ELECTRON SYSTEMS 63
2.8 NONCOVALENT INTERACTIONS 66
CHAPTER SUMMARY 70
Chapter 3 THE CONFORMATIONS OF ORGANIC MOLECULES 77
3.1 CONFORMATIONS OF ACYCLIC COMPOUNDS 77
3.2 CONFORMATIONS OF CYCLIC COMPOUNDS 82
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3.3 CONFORMATIONS OF SUBSTITUTED CYCLOHEXANES 87
3.4 CONFORMATIONS OF OTHER CYCLIC COMPOUNDS 97
CHAPTER SUMMARY 100
Chapter 4 THE STEREOCHEMISTRY OF ORGANIC MOLECULES 105
4.1 GEOMETRIC ISOMERS OF ALKENES 105
4.2 CHIRALITY AND ENANTIOMERS 110
4.3 DIASTEREOMERS 123
4.4 FISCHER PROJECTIONS 127
4.5 REACTION STEREOCHEMISTRY: A PREVIEW 129
CHAPTER SUMMARY 130
Chapter 5 CHEMICAL REACTIONS AND MECHANISMS 137
5.1 GENERAL ASPECTS OF REACTIONS 137
5.2 ACID–BASE REACTIONS 143
5.3 REACTION MECHANISMS 154
5.4 REACTION COORDINATE DIAGRAMS 159
5.5 REACTIONS IN BIOLOGICAL SYSTEMS 165
CHAPTER SUMMARY 171
Chapter 6 SUBST ITUTION REACTIONS OF ALKYL HALIDES 177
6.1 FUNDAMENTAL ASPECTS OF SUBSTITUTION REACTIONS 177
6.2 THE SN1 REACTION OF ALKYL HALIDES 183
6.3 THE SN2 REACTION OF ALKYL HALIDES 196
6.4 A COMPARISON OF THE SN1 AND SN2 MECHANISMS 204
CHAPTER SUMMARY 205
Chapter 7 SUBST ITUTION REACTIONS OF ALCOHOLSAND RELATED COMPOUNDS 211
7.1 SUBSTITUTION REACTIONS OF ALCOHOLS 211
7.2 SUBSTITUTION REACTIONS OF ETHERS AND EPOXIDES 218
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7.3 SUBSTITUTION REACTIONS OF THIOLS AND THIOETHERS 226
7.4 SUBSTITUTION REACTIONS IN BIOCHEMICAL SYSTEMS 228
CHAPTER SUMMARY 231
Chapter 8 EL IMINATION REACTIONS OF ALKYLHALIDES, ALCOHOLS, AND RELATEDCOMPOUNDS 239
8.1 THE E1 REACTION 240
8.2 THE E2 REACTION 246
8.3 SUBSTITUTION VERSUS ELIMINATION 253
8.4 ELIMINATION REACTIONS IN BIOLOGY 257
CHAPTER SUMMARY 259
Chapter 9 ADDIT ION REACTIONS OF ALKENES AND ALKYNES 267
9.1 ELECTROPHILIC ADDITION REACTIONS OF ALKENES 267
9.2 ELECTROPHILIC ADDITION REACTIONS OF ALKYNES 276
9.3 THE FORMATION OF CARBON–CARBON BONDS 279
9.4 HYDROBORATION REACTIONS OF π BONDS 285
9.5 THE ADDITION OF CARBENES TO π BONDS 293
CHAPTER SUMMARY 295
Chapter 10 ADDIT ION REACTIONS OF CONJUGATED DIENES 303
10.1 THE STRUCTURES OF DIENES 303
10.2 BONDING IN CONJUGATED DIENES 307
10.3 ELECTROPHILIC ADDITION TO CONJUGATED DIENES 313
10.4 THE DIELS–ALDER REACTION 317
CHAPTER SUMMARY 324
Chapter 11 OXIDATION AND REDUCTION REACTIONS 331
11.1 OXIDATION STATES IN ORGANIC MOLECULES 331
11.2 HYDROGENATION REACTIONS 334
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xii CONTENTS
11.3 OXIDATION REACTIONS OF ALKENES 338
11.4 OXIDATION REACTIONS OF ALCOHOLS 346
11.5 OXIDATION REACTIONS OF AMINES 353
CHAPTER SUMMARY 355
Chapter 12 FREE RADICAL REACTIONS 363
12.1 FREE RADICAL HALOGENATION REACTIONS 363
12.2 REDUCTION VIA RADICAL INTERMEDIATES 374
12.3 FREE RADICAL ADDITION REACTIONS 378
12.4 OXIDATION VIA RADICAL INTERMEDIATES 382
CHAPTER SUMMARY 389
Chapter 13 PROTON AND CARBON NMRSPECTROSCOPY 397
13.1 CHEMICAL SHIFTS AND PROTON EQUIVALENCE 398
13.2 SPIN COUPLING IN SIMPLE SYSTEMS 408
13.3 INTERPRETING AND PREDICTING 1H NMR SPECTRA 413
13.4 SPIN COUPLING IN MORE COMPLEX SYSTEMS 420
13.5 CARBON NMR SPECTRA 426
13.6 INTERPRETING 13C NMR SPECTRA 430
CHAPTER SUMMARY 435
Chapter 14 DETERMINING THE STRUCTURES OF ORGANIC MOLECULES 445
14.1 ANALYTICAL DATA IN STRUCTURE DETERMINATIONS 445
14.2 MASS SPECTROMETRY 449
14.3 INFRARED SPECTROSCOPY 458
14.4 COMBINED STRUCTURE DETERMINATION EXERCISES 470
CHAPTER SUMMARY 478
Chapter 15 ORGANOMETALL IC REAGENTS AND CHEMICAL SYNTHESIS 487
15.1 CARBON–CARBON BOND FORMATION 487
15.2 ORGANOMAGNESIUM AND LITHIUM COMPOUNDS 489
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15.3 TRANSITION METAL ORGANOMETALLIC COMPOUNDS 498
15.4 RETROSYNTHESIS 506
15.5 SELECTIVITY CRITERIA IN SYNTHESIS 511
CHAPTER SUMMARY 516
Chapter 16 ASYMMETRIC REACTIONS AND SYNTHESIS 525
16.1 CHIRAL COMPOUNDS 525
16.2 ENANTIOMERIC RESOLUTION 528
16.3 ASYMMETRIC SYNTHESIS 530
16.4 ENANTIOSELECTIVE ADDITION REACTIONS 538
16.5 SYNTHETIC DESIGN OF CHIRAL MOLECULES 548
CHAPTER SUMMARY 554
Chapter 17 THE CHEMISTRY OF BENZENE AND ITS DERIVATIVES 561
17.1 STRUCTURAL ASPECTS OF AROMATIC MOLECULES 562
17.2 ELECTROPHILIC SUBSTITUTION REACTIONS OF BENZENE 569
17.3 ELECTROPHILIC SUBSTITUTION REACTIONS OF BENZENE DERIVATIVES 574
17.4 OTHER REACTIONS OF BENZENE AND ITS DERIVATIVES 587
CHAPTER SUMMARY 594
Chapter 18 NUCLEOPHIL IC ADDIT ION REACTIONS OFALDEHYDES AND KETONES 605
18.1 GENERAL ASPECTS OF NUCLEOPHILIC ADDITION REACTIONS 606
18.2 NUCLEOPHILIC ADDITION REACTIONS 608
18.3 REDUCTION REACTIONS OF ALDEHYDES AND KETONES 612
18.4 OXIDATION REACTIONS OF ALDEHYDES AND KETONES 622
CHAPTER SUMMARY 625
Chapter 19 ADDIT ION–SUBSTITUTION REACTIONS OF ALDEHYDES AND KETONES:CARBOHYDRATE CHEMISTRY 635
19.1 HEMIACETALS AND ACETALS 636
19.2 ACETALS AS PROTECTING GROUPS 640
19.3 CARBOHYDRATES 643
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19.4 GLYCOSIDES 651
19.5 OXIDATION AND REDUCTION REACTIONS OF CARBOHYDRATES 658
CHAPTER SUMMARY 661
Chapter 20 ADDIT ION–EL IMINATION REACTIONS OF ALDEHYDES AND KETONES 669
20.1 COMPOUNDS WITH CARBON–NITROGEN DOUBLE BONDS 669
20.2 IMINE CHEMISTRY AND BIOCHEMISTRY 675
20.3 ENAMINES 682
20.4 YLIDES 684
CHAPTER SUMMARY 691
Chapter 21 ADDIT ION–EL IMINATION REACTIONS OF CARBOXYLIC ACIDS AND DERIVATIVES 701
21.1 GENERAL ASPECTS OF STRUCTURE AND REACTIVITY 702
21.2 REACTIONS OF CARBOXYLIC ACIDS 706
21.3 THE CHEMISTRY OF ACID CHLORIDES, THIOESTERS, AND ANHYDRIDES 710
21.4 THE CHEMISTRY OF ESTERS 715
21.5 THE CHEMISTRY OF AMIDES 719
21.6 THE CHEMISTRY OF NITRILES 724
21.7 REACTIONS WITH ORGANOMETALLIC COMPOUNDS 725
21.8 REDUCTION REACTIONS OF CARBOXYLIC ACIDS AND DERIVATIVES 728
CHAPTER SUMMARY 731
Chapter 22 THE ACID–BASE CHEMISTRY OF CARBONYL COMPOUNDS 745
22.1 ACIDITY OF CARBONYL COMPOUNDS 745
22.2 ENOLS AND ENOLATE IONS 751
22.3 REACTIONS OF ENOLATE IONS 759
22.4 DICARBONYL COMPOUNDS 766
22.5 REACTIONS OF AMIDE AND IMIDE IONS 772
CHAPTER SUMMARY 775
xiv CONTENTS
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Chapter 23 THE NUCLEOPHIL IC ADDIT ION REACTIONSOF ENOLATE IONS 787
23.1 THE ALDOL REACTION 787
23.2 CROSSED-ALDOL REACTIONS 791
23.3 THE CLAISEN CONDENSATION 802
23.4 CROSSED-CLAISEN CONDENSATIONS 806
CHAPTER SUMMARY 816
Chapter 24 CONJUGATE ADDIT ION REACTIONS OF UNSATURATED CARBONYL COMPOUNDS 823
24.1 α,β-UNSATURATED CARBONYL COMPOUNDS 824
24.2 CONJUGATE ADDITION REACTIONS 827
24.3 CONJUGATE ADDITION REACTIONS OF CARBANIONS 834
24.4 REDUCTION REACTIONS 843
CHAPTER SUMMARY 848
Chapter 25 THE CHEMISTRY OF POLYCYCLIC AND HETEROCYCLIC ARENES 859
25.1 POLYCYCLIC AROMATIC COMPOUNDS 859
25.2 PYRIDINE AND RELATED HETEROCYCLES 864
25.3 PYRROLE AND RELATED HETEROCYCLES 873
25.4 AZOLES 879
CHAPTER SUMMARY 886
Chapter 26 POLYMERS AND POLYMERIZATION 893
26.1 POLYMERS AND THEIR PROPERTIES 893
26.2 CHAIN-GROWTH POLYMERIZATION 898
26.3 STEP-GROWTH POLYMERIZATION 904
26.4 MODIFICATION OF POLYMERS 911
CHAPTER SUMMARY 914
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Chapter 27 AMINO ACIDS, PEPT IDES, AND PROTEINS 921
27.1 AMINO ACIDS 921
27.2 CHEMICAL SYNTHESIS OF AMINO ACIDS 927
27.3 ASYMMETRIC SYNTHESIS OF AMINO ACIDS 930
27.4 PEPTIDE SYNTHESIS AND ANALYSIS 935
27.5 PROTEIN STRUCTURES 942
CHAPTER SUMMARY 947
Chapter 28 NUCLEIC ACIDS AND MOLECULAR RECOGNIT ION 953
28.1 NUCLEOSIDES AND NUCLEOTIDES 953
28.2 NUCLEIC ACID STRUCTURES 961
28.3 MOLECULAR RECOGNITION 969
28.4 CROWN ETHERS AND CRYPTANDS 969
28.5 CAVITY-CONTAINING MOLECULES 974
28.6 RECOGNITION USING HYDROGEN BONDS 977
CHAPTER SUMMARY 982
APPENDIX A-1
GLOSSARY G-1
INDEX I-1
xvi CONTENTS
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The manner of teaching organic chemistry has changed somewhat since my days as astudent in the early 1970s. Most notably, organic chemistry textbooks offer more andbetter descriptions of topics in related fields, such as biochemistry and materials sci-ence; the internet allows one to search for information about specific topics; and com-puter software is readily available for modeling chemical structures and reactions. Theoverall level of sophistication has also risen for the presentation of traditional themessuch as stereochemistry, bonding, reaction mechanisms, spectroscopy, and synthesis.
In spite of these changes, however, the mastery of organic chemistry as a course ofstudy still requires a sound knowledge of the principles of molecular structure andchemical reactivity, which are topics introduced in most general chemistry courses.With such a background, a student studying organic chemistry begins to focus on amore limited set of atomic building blocks, particularly of carbon and its elementalneighbors. And while the study of a smaller portion of the periodic table might be ex-pected to be easily manageable, understanding organic chemistry can still seem over-whelming because of the diverse ways that this handful of elements can combine andinteract. To learn organic chemistry, one must grasp the recurring patterns that corre-late the presented facts.
Toward that end, this textbook organizes and discusses the patterns of chemical re-activity, which constitutes the majority of the subject matter, by combining informationabout the structures of functional groups (the reactive portions of a molecule) with thereaction mechanisms (pathways of chemical reactions) that these functional groups un-dergo. This approach differs from the one presented in many other texts, which de-scribe every type of reaction that can occur for a given functional group; each approachhas its advantages and disadvantages. The one I have utilized here evolved from my ob-jective to integrate discussions about biochemical processes with the types of reactionsthat are carried out in chemistry laboratories. With the use of two points of reference—structures and mechanisms—the similarities that associate biochemical and syntheticreactions can be appreciated more easily.
ORGANIZATION OF THE TEXT
A sound knowledge of structures, bonding, and stereochemistry—the three-dimen-sional arrangements and shapes of molecules—is required in order to understand thepatterns of chemical reactivity. For that reason, this book begins in Chapters 1–4 witha detailed treatment of molecular structures. After Chapter 5, which describes somegeneral aspects of chemical reactions, specific transformations are presented in thenext several chapters.
Spectroscopic methods are then covered in Chapters 13 and 14 (and used in sub-sequent chapters), with the emphasis in the first of these two chapters on nuclear mag-netic resonance (NMR) spectroscopy. Chapter 14 introduces other analytical methodsand integrates a number of techniques for the elucidation of molecular structures.
The topic of chemical synthesis constitutes a sizable portion of Chapters 15 and 16,with the latter focusing on enantioselective reactions. As with the spectroscopic meth-ods presented in the previous two chapters, synthetic methods are used throughout theremainder of the text.
Chapter 17 summarizes the structures and reactions of aromatic compounds, andthen the next several chapters present information about the reactions associatedwith the carbon–oxygen double bond, a structural feature of organic molecules that is
PREFACE
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pervasive in biochemical systems. Chapters 18–24 pay particular attention to chemicalreactions that occur in nature.
The final four chapters cover specific topics that make use of the basic structuresand reactions that have already been presented. The closing two chapters describe thechemistry of amino and nucleic acids, which establish the background for subsequentstudies in biology, biochemistry, and molecular biology.
EXERCISES
Rodger Griffin, Jr., who taught me organic chemistry, was fond of saying that organicchemistry was best learned by solving problems and not by reading chapter-by-chapteras one would do for a history or philosophy course. This text has many exercises in-corporated within the text as well as at the end of each chapter. Furthermore, this sec-ond edition has included many more examples (solved exercises) within the chaptersso that students can see successful approaches to problem solving. The accompanyingSolutions to Exercises book has the answer to every exercise; in many instances, the ap-proach needed to work toward the answer is included along with the factual solution.
xviii PREFACE
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“Organic Chemistry” at most colleges and universities carries the unfortunate status ofbeing among the more difficult and demanding courses offered. With its position inthe curriculum as the prerequisite for many upper level chemistry, biology, and phar-macy courses, its negative repute is unrivaled. No wonder many students refer to thistwo-semester sequence as the “premed weed-out courses!”
Your experience does not have to be that way, however. Below are listed several sug-gestions I make at the beginning of each semester aimed at maximizing my students’success in this subject.
• Go to class and participate.
I have written as clearly about organic chemistry as I can, but let’s be honest—if you could learn this stuff on your own by reading the book and working ex-ercises, then you’re a whiz kid and going to class probably won’t matter. If you’rea typical student, however, verbal explanations will help, and that’s one thingthat class is about. It’s also about seeing how problems are solved and how oth-ers look at them. Students who genuinely participate usually learn a lot. Theyalso impress their professors, which can’t hurt.
• Be prepared.
Read the sections in the book that will be covered in class on a given day andthink about how the material fits with what you know or have covered recently.Much of the material that you will learn in your organic chemistry courses isconceptually new—organic chemistry is not a repeat of general chemistry. If youhave an idea beforehand about the key points of the topics being discussed, youwill learn the material faster. On the other hand, don’t spend hours and hoursreading and taking notes—organic chemistry is not an English or history course.
• Study (even a little) every day.
Easier said than done: I had many teachers tell me this when I was a student, andI myself have said the same thing to countless students. Does anyone listen?Maybe for about a week at the beginning of the semester. Then the pressures oflife and your other courses get in the way, and you’re back to cramming thenight before an exam. I learned this lesson by experience: If you want to do well,studying one hour each day of a week is at least twice as good as studying sevenhours once each week.
• Work the assigned exercises.
Understanding organic chemistry is about seeing and learning the recurringpatterns that correlate the many facts being presented. Those who see and learnthese patterns—among structures, chemical reactions, molecular properties—usually do well. Those who don’t (or can’t) learn these patterns will struggle.Your brain may be wired in ways that make it difficult for you to see the under-lying design of organic chemistry. There’s not much that can be done about this,but it doesn’t mean you will fail—it just means that you may have to work harderthan others in order to succeed. The best way to learn these patterns is to workproblems. And then work more problems. And then work even more problems.
The answers to many of the study exercises may not be obvious when you firstread the problem. Do not give up quickly and do not consult the Solutions to Ex-ercises book without making a determined effort to solve the exercise on your own.Many people can read an answer and understand it. Don’t be fooled into think-
TO THESTUDENT
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ing that you can solve problems because you understand the answers when yousee them. Write the solution to each exercise on paper. Even if the answer seemsobvious, writing it will help you remember and learn. Also, do several problemsbefore you look at their answers. If you look up the solution as you do each ex-ercise, you may catch a glimpse of the answer to the next problem. The result isthat you are not really working the next one.
• Make flash cards.
In addition to doing the study exercises, some students find it useful to make“flash cards,” especially to learn the many chemical reactions that you will haveto commit to memory. A set of cards with important information makes it easyto review the course material while you’re waiting for a movie to begin, sittingbetween classes, riding the bus, or any time during the day when you may havefive or ten minutes to study. Organic chemistry is a cumulative subject. At theend of the semester, you will need to know material presented on the first dayof the course just as much as you will need to know it for the first exam. A set ofcards will be invaluable for review. NOTE WELL: Using flash cards prepared bysomeone else has limited benefit. Much of their advantage comes from havingto think about structures and chemical reactions enough to prepare the cards.
• Before an exam, get a good night of sleep.
Many of you will be expected to solve problems on exams that you have not seenbefore. If you have studied regularly, then being alert and relaxed is more im-portant than last minute cramming. If you haven’t studied regularly, you’reprobably in trouble whether you’re rested or not. So you might as well be rested.
• Get help early.
The sooner you realize that you’re in trouble, the better. Go talk to your pro-fessor, a teaching assistant, or a tutor. Or form a study group. Some students findthat other students can help them sort out confusing facts as well as anyone, andan added benefit is a measure of accountability to your peers.
I am always interested to hear from students about what works and what doesn’t. Ifyou find factual errors or discussions that are confusing, please send me an email to letme know ([email protected]). Such comments are important to keep this text evolvingso that it is as useful as possible to its readers—you, the students. Sometimes the mostinnocent remark can make me understand where a student has lost the thread ofthought that winds through the presentation of a particular topic, and it is that type ofinput that teaches me and helps me to teach others better.
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As noted in the Preface to the first edition of this book, I became dissatisfied with manyorganic chemistry texts when I started teaching biochemistry. The same students whohad done well in organic chemistry could not seem to remember even simple reactionsrelated to the ones being covered in the biochemistry course. Yet I remembered, forexample, covering the structures and reactions of carbohydrates, amino acids, and nu-cleic acids in the previous courses. I concluded that the text we were using had failedto associate the material shared by the two disciplines because the topics related to bio-chemistry were segregated within their own chapters and students had compartmen-talized the material they had learned, mentally labeling the information as “organicchemistry” or “biochemistry.”
In writing this textbook, and especially this second edition, my goal has been to in-tegrate the information about many of the fundamental biochemical reactions with thecorresponding transformations that are carried out in organic chemistry laboratories.Many who teach the biochemistry courses will give scant attention to the details of thechemical reactions that constitute metabolic processes, which I think is useful infor-mation to be learned by the students who hope to pursue a career in the health pro-fessions and who constitute the majority of those taking organic chemistry. The organicchemistry courses provide the best (and perhaps only) forum to make students awareof such details. I believe that this awareness can be facilitated by illustrating the paral-lels between biochemical processes and the simpler chemical reactions that are beingdiscussed. Even if students cannot remember specific facts later, they will likely recallthat such associations exist; and they will be more likely later to dig out their organicchemistry texts to review these topics when they want to understand a particular bio-chemical process at the molecular level. As most organic chemistry instructors know,the key for understanding chemical reactions resides in comprehending their mecha-nisms. Therefore, reaction mechanisms comprise the major organizational theme ofthis text, and their details are presented in order to illustrate and underscore the sim-ilarities between synthetic and biochemical processes.
To develop these connections about chemical reactions, however, one cannot glossover the facts about molecular structures, stereochemistry, and thermodynamics.Therefore, these topics are developed in the first five chapters of this book, and I trustthey are presented with sufficient depth that students who intend to become organicchemists will not be shortchanged. Toward that same end of serving the future chemistsin the organic chemistry classes, I have also included presentations of synthetic reac-tions that appear frequently in the current literature (e.g., the Misunobu, Swern, andSuzuki reactions) as well as topics such an enantioselective synthesis and molecularrecognition.
NEW TO THIS EDIT ION
Based on the feedback given to me by hundreds of students as well as from the critiquesof the dedicated reviewers listed in the Acknowledgments, several of whom taughttheir courses using the first edition of this text, I have made changes that are meant tomake the material better organized and easier to understand. I estimate that one-quar-ter to one-third of the text has been completely rewritten. A substantial change in thecontent comprises the inclusion of more examples (solved exercises).
As is often true of second editions, a number of the more specialized topics (andchemical reactions) that appeared in the first edition have been left out. Most no-tably absent is the first chapter of the previous edition, which provided a historical
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perspective of organic chemistry. The current first chapter—on basic structures andnomenclature—still stands as the organizational pillar of structural chemistry for thebook, but it has been modified by incorporating the strategies for naming compounds(which was Appendix A in the first edition) and eliminating the discussions of sometypes of groups that are better saved until later in the book (esters, in particular).
The first chapter that concerns a specific type of chemical reaction (nucleophilicsubstitution) has been expanded and divided into two chapters in this edition (Chap-ters 6 and 7). In this way, alkyl halides and alcohol substitution reactions are treatedseparately, and some sulfur-containing molecules are now included in the chapter onalcohols.
The oxidation reactions of alcohols have been removed from the chapter on elim-ination reactions (first edition), and a separate chapter on reduction and oxidation re-actions has been created here (Chapter 11). The information in this chapter alsoincludes discussions about the reduction and oxidation reactions of alkenes, whichwere covered previously in a chapter about alkene addition reactions. Also, the chem-istry of dienes, including the Diels–Alder reaction, have been collected in a chapterseparate from the one devoted to the addition reactions of simple alkenes.
The order of topics in the chapters that present spectroscopic methods has beenreversed from that in the previous edition, so nuclear magnetic resonance spectroscopyis now covered first. The subsequent spectroscopy chapter integrates the use of severaltechniques, including elemental analysis, for the elucidation of molecular structures.
The chapter that introduces synthetic methods has been largely preserved fromthe first edition, but it is followed directly by the chapter on enantioselective synthe-sis (previously, these two chapters were separated by the spectroscopy chapters). Thediscussion of enantioselective reactions has been completely rewritten, and its em-phasis has been changed to encourage students to think about designing enantiose-lective syntheses without having to memorize a lot of details about specific reagentsand conditions.
The topic of aromatic compounds (benzene and its derivatives) has been moved(from Chapter 12 in the first edition to Chapter 17 in the second) with the material onpolycyclic arenes combined with an abbreviated discussion of heterocycles in Chapter24. The presentations about diazonium compounds and nucleophilic aromatic substi-tution reactions, which were in the chapter on nitrogen-containing compounds (Chap-ter 23, first edition), have been incorporated into Chapter 17 (second edition).
The chapters describing carbonyl compounds have been kept largely intact. Themost significant change is the division of Chapter 17 (first edition) about aldehydes, ke-tones, and carbohydrates into two chapters in the current edition. The division hasbeen made according to the reaction mechanisms involved (nucleophilic addition ver-sus nucleophilic addition—substitution), not according to the functional groups thatare undergoing the reactions.
The chapter on nitrogen-containing compounds (Chapter 23 in the first edition)has been parceled in this edition among several chapters, as appropriate. In contrast,the discussions of polymer chemistry, which were interspersed throughout the book inthe first edition, have been collected to form Chapter 26 in this edition. Some basicpresentations of polymerization processes have been left in the earlier chapters to showthe mechanistic similarities to other fundamental reactions, but many of the details aredeveloped in this later chapter.
The final two chapters on amino and nucleic acids, including the topic of molec-ular recognition, are similar in style and content to those in the first edition.
xxii TO THE INSTRUCTOR
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For its creation, a good textbook requires participation by many people besides the au-thor, and I am profoundly grateful to the following individuals for the work they did tomake this second edition a reality.
With their comments and questions while using the first edition of this text, the stu-dents that I have taught during the past several years contributed invaluably to the de-velopment and writing of this second edition.
My daughter Courtney, who is now a graduate student in chemistry at GeorgiaTech, was especially helpful during the early and middle stages of the writing processas she helped with the typing, both of the text and Solutions to Exercises. Her work at Syn-thematix (a local startup company that has since been acquired by Symyx Technolo-gies, Inc.), gave her the experience to offer suggestions that helped organize severaltopics better.
My professional peers offered much in the way of their technical comments, cor-rections, and support. At the University of North Carolina at Chapel Hill, my colleaguesMaurice Brookhart, Joseph DeSimone, Richard Hiskey, Paul Kropp, and Gary Pielakshared their valuable expertise on specific topics that appeared in both editions. PaulKropp suggested some especially constructive changes for this edition as a result ofusing the book in the Honors courses at UNC. At other institutions, the following per-sons read all or parts of the manuscripts and provided detailed critiques and sugges-tions that helped make the text more readable, more accurate, and more pedagogical.
SECOND EDITION
David Bergbreiter Texas A&M University Neil Marsh University of MichiganRené Boeré University of Lethbridge William le Noble SUNY StonybrookAndrew Bororvik University of Kansas Jennifer Radkiewicz Old Dominion UniversityDavid Bundle University of Alberta Christian Rojas Barnard CollegeMarjorie Caserio UC, San Diego Dalibor Sames Columbia UniversityChuck Doubleday Columbia University Martin Semmelhack Princeton UniversityAndrew French Albion College J. William Suggs Brown UniversityWarren Giering Boston University Marcus Thomsen Franklin & Marshall CollegeJohn Hubbard Marshall University F. Dean Toste UC, BerkeleySteven Kass University of Minnesota Nick Turro Columbia UniversitySusan King UC, Irvine Nanine Van Draanen California Polytechnic State Michael Zagorski Case Western Reserve University
University
FIRST EDITION
Tom Bond UC, San Diego Dagmar Ringe Brandeis UniversityMark Burk Duke University Charles Rose University of NevadaKeith Buszek Kansas State University John Swenson Ohio State UniversityBarry Carpenter Cornell University K. Barry Sharpless Scripps InstituteSherin Halfon UC, San Francisco Bill Suggs Brown UniversityBob Hanson St. Olaf College Audrey Miller University of ConnecticutF. Chris Pigge University of Missouri Carol Dempster Long Island Research
at St. Louis Institute
During and after the writing process, a large amount of work is required to pro-duce a finished book from hundreds of files containing the text and figures. As a publisher, Bruce Armbruster is among the best at orchestrating this transformation,
ACKNOWLEDGMENTS
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and along with Kathy Armbruster and Jane Ellis, this team at University Science Booksdid their usual excellent job. Mary Castellion, herself an author, was an especially ef-fective collaborator during the writing of this edition in helping me to edit the previ-ous text and to present more succinctly and accurately some of the difficult concepts.Jeannette Stiefel did a masterful job with the copy edit, while Ann Knight coordinatedthe production.
The accompanying Solutions to Exercises was originally fashioned with significanthelp from Julius Beau Lucks, a former undergraduate student who was a ChurchillScholar after graduation and is currently a graduate student in chemistry at HarvardUniversity. Beau worked every exercise in the first edition and checked their solutions.Subsequent groups of students have found and corrected some errors in those solu-tions; the second edition of the Solutions to Exercises text was copyedited and checked byChristine Cleveland, a student in my 2002–03 course who will be attending theUNC–CH School of Medicine beginning in the 2005 fall semester.
I sincerely thank all of you for the efforts and support you have contributed to thiscreative process.
Thomas Sorrell
Chapel Hill
xxiv ACKNOWLEDGMENTS
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