Ouellette / Rawn Principles of Organic Chemistry

1. Auflage 2015
ISBN: 978-0-12-802634-2
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 496 Seiten

Class-tested and thoughtfully designed for student engagement, Principles of Organic Chemistry provides the tools and foundations needed by students in a short course or one-semester class on the subject. This book does not dilute the material or rely on rote memorization. Rather, it focuses on the underlying principles in order to make accessible the science that underpins so much of our day-to-day lives, as well as present further study and practice in medical and scientific fields. This book provides context and structure for learning the fundamental principles of organic chemistry, enabling the reader to proceed from simple to complex examples in a systematic and logical way. Utilizing clear and consistently colored figures, Principles of Organic Chemistry begins by exploring the step-by-step processes (or mechanisms) by which reactions occur to create molecular structures. It then describes some of the many ways these reactions make new compounds, examined by functional groups and corresponding common reaction mechanisms. Throughout, this book includes biochemical and pharmaceutical examples with varying degrees of difficulty, with worked answers and without, as well as advanced topics in later chapters for optional coverage. - Incorporates valuable and engaging applications of the content to biological and industrial uses - Includes a wealth of useful figures and problems to support reader comprehension and study - Provides a high quality chapter on stereochemistry as well as advanced topics such as synthetic polymers and spectroscopy for class customization

Robert J. Ouellette, Professor Emeritus, Department of Chemistry, The Ohio State University.

Autoren/Hrsg.

Ouellette, Robert J.

Rawn, J. David

Inhaltsverzeichnis

1;Front Cover ;1
2;Principles of Organic Chemistry ;4
3;Copyright ;5
4;Table of Contents ;6
5;Chapter 1: Structure of Organic Compounds ;12
5.1;1.1 Organic and Inorganic Compounds ;12
5.2;1.2 Atomic Structure ;12
5.3;1.3 Types of Bonds ;15
5.4;1.4 Formal Charge ;18
5.5;1.5 Resonance Structures ;19
5.6;1.6 Predicting the Shapes of Simple Molecules ;21
5.7;1.7 Orbitals and Molecular Shapes ;22
5.8;1.8 Functional Groups ;26
5.9;1.9 Structural Formulas ;29
5.10;1.10 Isomers ;34
5.11;1.11 Nomenclature ;36
5.12;Exercises ;38
6;Chapter 2: Properties of Organic Compounds ;44
6.1;2.1 Structure and Physical Properties ;44
6.2;2.2 Chemical Reactions ;49
6.3;2.3 Acid-Base Reactions;50
6.4;2.4 Oxidation-Reduction Reactions;52
6.5;2.5 Classification of Organic Reactions;55
6.6;2.6 Chemical Equilibrium and Equilibrium Constants ;56
6.7;2.7 Equilibria in Acid-Base Reactions ;58
6.8;2.8 Effect of Structure on Acidity ;60
6.9;2.9 Introduction to Reaction Mechanisms ;62
6.10;2.10 Reaction Rates ;65
6.11;Exercises ;69
7;Chapter 3: Alkanes and Cycloalkanes ;76
7.1;3.1 Classes of Hydrocarbons ;76
7.2;3.2 Alkanes ;76
7.3;3.3 Nomenclature of Alkanes ;79
7.4;3.4 Conformations of Alkanes ;83
7.5;3.5 Cycloalkanes ;86
7.6;3.6 Conformations of Cycloalkanes ;89
7.7;3.7 Physical Properties of Alkanes ;92
7.8;3.8 Oxidation of Alkanes and Cycloalkanes ;94
7.9;3.9 Halogenation of Saturated Alkanes ;95
7.10;3.10 Nomenclature of Haloalkanes ;98
7.11;Summary of Reactions ;100
7.12;Exercises ;101
8;Chapter 4: Alkenes and Alkynes ;106
8.1;4.1 Unsaturated Hydrocarbons ;106
8.2;4.2 Geometric Isomerism ;110
8.3;4.3 E,Z Nomenclature of Geometrical Isomers ;112
8.4;4.4 Nomenclature of Alkenes and Alkynes ;114
8.5;4.5 Acidity of Alkenes and Alkynes ;117
8.6;4.6 Hydrogenation of Alkenes and Alkynes ;118
8.7;4.7 Oxidation of Alkenes and Alkynes ;121
8.8;4.8 Addition Reactions of Alkenes and Alkynes ;122
8.9;4.9 Mechanism of Addition Reactions ;124
8.10;4.10 Hydration of Alkenes and Alkynes ;126
8.11;4.11 Preparation of Alkenes and Alkynes ;127
8.12;4.12 Alkadienes (Dienes) ;130
8.13;4.13 Terpenes ;131
8.14;Summary of Reactions ;135
8.15;Exercises ;137
9;Chapter 5: Aromatic Compounds ;144
9.1;5.1 Aromatic Compounds ;144
9.2;5.2 Aromaticity ;145
9.3;5.3 Nomenclature of Aromatic Compounds ;148
9.4;5.4 Electrophilic Aromatic Substitution ;150
9.5;5.5 Structural Effects in Electrophilic Aromatic Substitution ;154
9.6;5.6 Interpretation of Rate Effects ;156
9.7;5.7 Interpretation of Directing Effects ;159
9.8;5.8 Reactions of Side Chains ;161
9.9;5.9 Functional Group Modification ;163
9.10;5.10 Synthesis of Substituted Aromatic Compounds ;165
9.11;Summary of Reactions ;167
9.12;Exercises ;169
10;Chapter 6: Stereochemistry ;174
10.1;6.1 Configuration of Molecules ;174
10.2;6.2 Mirror Images and Chirality ;174
10.3;6.3 Optical Activity ;178
10.4;6.4 Fischer Projection Formulas ;179
10.5;6.5 Absolute Configuration ;181
10.6;6.6 Molecules with Multiple Stereogenic Centers ;184
10.7;6.7 Synthesis of Stereoisomers ;189
10.8;6.8 Reactions that Produce Stereogenic Centers ;190
10.9;6.9 Reactions that Form Diastereomers ;193
10.10;Exercises ;195
11;Chapter 7: Nucleophilic Substitution and Elimination Reactions ;200
11.1;7.1 Reaction Mechanisms and Haloalkanes ;200
11.2;7.2 Nucleophilic Substitution Reactions ;203
11.3;7.3 Nucleophilicity Versus Basicity ;205
11.4;7.4 Mechanisms of Substitution Reactions ;208
11.5;7.5 SN2 Versus SN1 Reactions ;211
11.6;7.6 Mechanisms of Elimination Reactions ;212
11.7;7.7 Effect of Structure on Competing Reactions ;214
11.8;Summary of Reactions ;217
11.9;Exercises ;217
12;Chapter 8: Alcohols and Phenols ;220
12.1;8.1 The Hydroxyl Group ;220
12.2;8.2 Physical Properties of Alcohols ;223
12.3;8.3 Acid-Base Reactions of Alcohols ;225
12.4;8.4 Substitution Reactions of Alcohols ;226
12.5;8.5 Dehydration of Alcohols ;227
12.6;8.6 Oxidation of Alcohols ;229
12.7;8.7 Synthesis of Alcohols ;232
12.8;8.8 Phenols ;237
12.9;8.9 Sulfur Compounds: Thiols and Thioethers ;240
12.10;Summary of Reactions ;242
12.11;Exercises ;243
13;Chapter 9: Ethers and Epoxides ;250
13.1;9.1 Structure of Ethers ;250
13.2;9.2 Nomenclature of Ethers ;251
13.3;9.3 Physical Properties of Ethers ;252
13.4;9.4 The Grignard Reagent and Ethers ;253
13.5;9.5 Synthesis of Ethers ;255
13.6;9.6 Reactions of Ethers ;256
13.7;9.7 Synthesis of Epoxides ;257
13.8;9.8 Reactions of Epoxides ;257
13.9;Summary of Reactions ;265
13.10;Exercises ;266
14;Chapter 10: Aldehydes and Ketones ;270
14.1;10.1 The Carbonyl Group ;270
14.2;10.2 Nomenclature of Aldehydes and Ketones ;272
14.3;10.3 Physical Properties of Aldehydes and Ketones ;274
14.4;10.4 Oxidation-Reduction Reactions of Carbonyl Compounds ;276
14.5;10.5 Addition Reactions of Carbonyl Compounds ;278
14.6;10.6 Synthesis of Alcohols from Carbonyl Compounds ;280
14.7;10.7 Addition Reactions of Oxygen Compounds ;283
14.8;10.8 Formation of Acetals and Ketals ;285
14.9;10.9 Addition of Nitrogen Compounds ;286
14.10;10.10 Reactivity of the .-Carbon Atom ;289
14.11;10.11 The Aldol Condensation ;290
14.12;Summary of Reactions ;293
14.13;Exercises ;295
15;Chapter 11: Carboxylic Acids and Esters ;298
15.1;11.1 Carboxylic Acids and Acyl Groups ;298
15.2;11.2 Nomenclature of Carboxylic Acids ;300
15.3;11.3 Physical Properties of Carboxylic Acids ;303
15.4;11.4 Acidity of Carboxylic Acids ;305
15.5;11.5 Synthesis of Carboxylic Acids ;308
15.6;11.6 Nucleophilic Acyl Substitution ;311
15.7;11.7 Reduction of Acyl Derivatives ;315
15.8;11.8 Esters and Anhydrides of Phosphoric Acid ;316
15.9;11.9 The Claisen Condensation ;319
15.10;Summary of Reactions ;320
15.11;Exercises ;322
16;Chapter 12: Amines and Amides ;326
16.1;12.1 Organic Nitrogen Compounds ;326
16.2;12.2 Bonding and Structure of Amines ;327
16.3;12.3 Structure and Classification of Amines and Amides ;328
16.4;12.4 Nomenclature of Amines and Amides ;330
16.5;12.5 Physical Properties of Amines ;333
16.6;12.6 Basicity of Nitrogen Compounds ;336
16.7;12.7 Solubility of Ammonium Salts ;339
16.8;12.8 Nucleophilic Reactions of Amines ;339
16.9;12.9 Synthesis of Amines ;342
16.10;12.10 Hydrolysis of Amides ;344
16.11;12.11 Synthesis of Amides ;345
16.12;Summary of Reactions ;345
16.13;Exercises ;347
17;Chapter 13: Carbohydrates ;354
17.1;13.1 Classification of Carbohydrates ;354
17.2;13.2 Chirality of Carbohydrates ;355
17.3;13.3 Hemiacetals and Hemiketals ;360
17.4;13.4 Conformations of Monosaccharides ;364
17.5;13.5 Reduction of Monosaccharides ;365
17.6;13.6 Oxidation of Monosaccharides ;365
17.7;13.7 Glycosides ;367
17.8;13.8 Disaccharides ;369
17.9;13.9 Polysaccharides ;373
17.10;Summary of Reactions ;376
17.11;Exercises ;377
18;Chapter 14: Amino Acids, Peptides, and Proteins ;382
18.1;14.1 Proteins Andpolypeptides ;382
18.2;14.2 Amino Acids ;382
18.3;14.3 Acid-Base Properties of .-Amino Acids ;383
18.4;14.4 Isoionic Point ;387
18.5;14.5 Peptides ;388
18.6;14.6 Peptide Synthesis ;391
18.7;14.7 Determination of Protein Structure ;393
18.8;14.8 Protein Structure ;397
18.9;Exercises ;404
19;Chapter 15: Synthetic Polymers ;408
19.1;15.1 Natural and Synthetic Macromolecules ;408
19.2;15.2 Structure and Properties of Polymers ;408
19.3;15.3 Classification of Polymers ;410
19.4;15.4 Methods of Polymerization ;412
19.5;15.5 Addition Polymerization ;415
19.6;15.6 Copolymerization of Alkenes ;416
19.7;15.7 Cross-Linked Polymers ;417
19.8;15.8 Stereochemistry of Addition Polymerization ;419
19.9;15.9 Condensation Polymers ;421
19.10;15.10 Polyesters ;422
19.11;15.11 Polycarbonates ;424
19.12;15.12 Polyamides ;425
19.13;15.13 Polyurethanes ;426
19.14;Exercises ;427
20;Chapter 16: Spectroscopy ;432
20.1;16.1 Spectroscopic Structure Determination ;432
20.2;16.2 Spectroscopic Principles ;433
20.3;16.3 Ultraviolet Spectroscopy ;435
20.4;16.4 Infrared Spectroscopy ;436
20.5;16.5 Nuclear Magnetic Resonance Spectroscopy ;442
20.6;16.6 Spin-Spin Splitting ;446
20.7;16.7 13C NMR Spectroscopy ;450
20.8;Exercises ;453
21;Solutions to In-Chapter Problems ;458
22;Index ;488

Leseproben

1

Structure of Organic Compounds

1.1 Organic and Inorganic Compounds

Organic chemistry began to emerge as a science about 200 years ago. By the late eighteenth century, substances were divided into two classes called inorganic and organic compounds. Inorganic compounds were derived from mineral sources, whereas organic compounds were obtained only from plants or animals. Organic compounds were more difficult to work with in the laboratory, and decomposed more easily, than inorganic compounds. The differences between inorganic and organic compounds were attributed to a “vital force” associated with organic compounds. This unusual attribute was thought to exist only in living matter. It was believed that without the vital force, organic compounds could not be synthesized in the laboratory. However, by the mid-nineteenth century, chemists had learned both how to work with organic compounds and how to synthesize them.

Organic compounds always contain carbon and a limited number of other elements, such as hydrogen, oxygen, and nitrogen. Compounds containing sulfur, phosphorus, and halogens are known but are less prevalent. Most organic compounds contain many more atoms per structural unit than inorganic compounds and have more complex structures. Common examples of organic compounds include the sugar sucrose (C12H22O11), vitamin B2 (C117H120N4O6), cholesterol (C27H46O), and the fat glycerol tripalmitate (C51H98O6). Some organic molecules are gigantic. DNA, which stores genetic information, has molecular weights that range from 3 million in Escherichia coli to 2 billion for mammals.

Based on the physical characteristics of compounds, such as solubility, melting point, and boiling point, chemists have proposed that the atoms of the elements are bonded in compounds in two principal ways—ionic bonds and covalent bonds. Both types of bonds result from a change in the electronic structure of atoms as they associate with each other. Thus, the number and type of bonds formed and the resultant shape of the molecule depend on the electron configuration of the atoms. Therefore, we will review some of the electronic features of atoms and the periodic properties of the elements before describing the structures of organic compounds.

1.2 Atomic Structure

Each atom has a central, small, dense nucleus that contains protons and neutrons; electrons are located outside the nucleus. Protons have a + 1 charge; electrons have a - 1 charge. The number of protons, which determines the identity of an atom, is given as its atomic number. Since atoms have an equal number of protons and electrons and are electrically neutral, the atomic number also indicates the number of electrons in the atom. The number of electrons in the hydrogen, carbon, nitrogen, and oxygen atoms are one, six, seven, and eight, respectively.

The periodic table of the elements is arranged by atomic number. The elements are arrayed in horizontal rows called periods and vertical columns called groups. In this text, we will emphasize hydrogen in the first period and the elements carbon, nitrogen, and oxygen in the second period. The electronic structure of these atoms is the basis for their chemical reactivity.

Atomic Orbitals

Electrons around the nucleus of an atom are found in atomic orbitals. Each orbital can contain a maximum of two electrons. The orbitals, designated by the letters s, p, d, and f, differ in energy, shape, and orientation. We need to consider only the s and p orbitals for elements such as carbon, oxygen, and nitrogen.

Orbitals are grouped in shells of increasing energy designated by the integers n = 1, 2, 3, 4,…, n. These integers are called principal quantum numbers. With few exceptions, we need consider only the orbitals of the first three shells for the common elements found in organic compounds.

Each shell contains a unique number and type of orbitals. The first shell contains only one orbital—the s orbital. It is designated 1s. The second shell contains two types of orbitals—one s orbital and three p orbitals.

An s orbital is a spherical region of space centered around the nucleus (Figure 1.1). The electrons in a 2s orbital are higher in energy than those in a 1s orbital. The 2s orbital is larger than the 1s orbital, and its electrons on average are farther from the nucleus. The three p orbitals in a shell are shaped like “dumbbells.” However, they have different orientations with respect to the nucleus (Figure 1.1). The orbitals are often designated px, py, and pz to emphasize that they are mutually perpendicular to one another. Although the orientations of the p orbitals are different, the electrons in each p orbital have equal energies.

Figure 1.1 Shapes of 2s and 2p Orbitals.

Electrons are pictured within a volume called an orbital. A “cloud” of negative charge surrounds the nucleus, which is located at the origin of the intersecting axes. (a) The s orbital is pictured as a sphere. (b) The three orbitals of the p subshell are arranged perpendicular to one another. Each orbital may contain two electrons. (c) Molecular model of a 2pz orbital.

Orbitals of the same type within a shell are often considered as a group called a subshell. There is only one orbital in an s subshell. An s subshell can contain only two electrons, but a p subshell can contain a total of six electrons within its px, py, and pz orbitals. Electrons are located in subshells of successively higher energies so that the total energy of all electrons is as low as possible. The order of increasing energy of subshells is 1s < 2s < 2p < 3s < 3p for elements of low atomic number. If there is more than one orbital in a subshell, one electron occupies each with parallel spins until all are half full. A single electron within an orbital is unpaired; two electrons with opposite spins within an orbital are paired and constitute an electron pair. The number and location of electrons for the first 18 elements are given in Table 1.1. The location of electrons in atomic orbitals is the electron configuration of an atom.

Table 1.1

Electron Configurations of First and Second Period Elements

H

1

1

1s1

He

2

2

1s2

Li

3

2

1

1s2 2s1

Be

4

2

2

1s2 2s2

B

5

2

2

1(?)

1s2 2s2 2p1

C

6

2

2

1 (?)

1 (?)

1s2 2s2 2p2

N

7

2

2

1 (?)

1 (?)

1 (?)

1s2 2s2 2p3

O

8

2

2

2(??)

1 (?)

1 (?)

1s2 2s2 2p4

F

9

2

2

2 (??)

2 (??)

1 (?)

1s2 2s2 2p5

Ne

10

2

2

2 (??)

2 (??)

2 (??)

1s2 2s2 2p6

Valence Shell Electrons

Electrons in filled, lower energy shells of atoms have no role in determining the structure of molecules, nor do they participate in chemical reactions. Only the higher energy electrons located in the outermost shell, the valence shell, participate in chemical reactions. Electrons in the valence shell are valence electrons. For example, the single electron of the hydrogen atom is a valence electron. The number of valence electrons for the common atoms contained in organic molecules is given by their group number in the periodic table. Thus carbon, nitrogen, and oxygen atoms have four, five, and six valence electrons, respectively. With this information we can understand how these elements combine to form the structure of organic compounds.

The physical and chemical properties of an element may be estimated from its position in the periodic table. Two principles that help us to explain the properties of organic compounds are atomic radius and electronegativity. The overall shape of an isolated atom is spherical, and the volume of the atom depends on the number of electrons and the energies of the electrons in occupied orbitals. The sizes of some atoms expressed as the atomic radius, in picometers, are given in Figure 1.2. The atomic radius for an atom does not vary significantly from one compound to another. Atomic radii increase from top to bottom in a group of the periodic table. Each successive member of a group has one additional energy level containing electrons located at larger distances from the nucleus. Thus, the atomic radius of sulfur is greater than that of oxygen, and the radii of the halogens increase in the order...