Joseph
C.
Sloop,
author
Structure
Function
Mechanism
About the Author
Dr. Joseph C. Sloop, Associate Professor, Georgia Gwinnett College
Dr. Sloop, a North Carolina native, completed requirements for his B. S. degree with Special
Attainments in Chemistry from Davidson College under the direction of Dr. Felix Carroll in organic
photochemistry in 1983. He was commissioned into the U. S. Army Chemical Corps upon
graduation. He then attended North Carolina State University (NCSU), completing work toward a
Master’s degree in Chemistry in fluorinated heterocycle synthesis under the direction of Dr. Carl
Bumgardner. He joined the faculty of the United States Military Academy (USMA) at West Point in
1990, where he taught general and organic chemistry. From 1994 -1996, he taught organic chemistry
and environmental toxicology at Drury College, Fort Leonard Wood campus. In 2000, he was
selected by the U. S. Army for doctoral training and returned to NCSU where he completed
requirements for a Ph.D. under the direction of Dr. David Shultz in organic magnetochemistry.
Upon graduation, Dr. Sloop rejoined the USMA faculty at West Point in 2003, teaching organic
chemistry and directing the undergraduate research program for the Department of Chemistry and
Life Science until 2009. Upon his retirement from military service, Dr. Sloop accepted a position as
Associate Professor in the School of Science and Technology at Georgia Gwinnett College, where he
currently teaches a variety of chemistry courses. He is the recipient of several teaching and research
awards with many scientific and science education papers to his credit as well as contributing author
to the 2007 text entitled Fluorine Chemistry Research Advances.
About the Book
This text is specifically designed to help introductory Organic Chemistry students understand the
fundamental concepts covered in undergraduate organic chemistry. The purpose of this book is
three-fold: to explode the misconceptions and misgivings that are prevalent regarding this vast
subject, provide additional insight for students on a number of concepts essential to mastery of
organic chemistry, and explore alternative learning strategies to assist the beginning organic chemistry
student in applying a specialized problem solving technique which centers on structure, function and
a mechanistic approach. Examples of key chemical transformations are dissected and analyzed to
assist students in improving their problem-solving skills. Each chapter contains a number of
additional problems and the solutions to those problems are provided at the end of each chapter.
Preface
What is it about organic chemistry that strikes such fear into the hearts of budding
scientists, doctors and chemists? Why do students approach this subject with trepidation?
Although these questions are not easily answered, over the years of teaching
organic chemistry we have learned how students think about organic chemistry. The
purpose of this book is three-fold: to explode the misconceptions and misgivings that are
prevalent regarding this vast subject, provide additional insight for students on a number
of concepts essential to mastery of organic chemistry, and explore alternative learning
strategies to assist the beginning organic chemistry student in applying a specialized
problem solving technique which centers on structure, function and a mechanistic
approach. The goal for the audience is to, given the appropriate tools, arrive at the
realization that introductory organic chemistry may not only be mastered, but may be
enjoyed as well.
Table of Contents
_____ Chapter Topic__________________________________________________
Chapter 1 – Studying for Success
Page___
1
1.1 Exploding the Myth
1.2 Being a Student of the Subject
1.3 Studying Organic Chemistry: What You must Know
1.4 Optimizing Your Lecture Experience
1.5 Working Additional Problems
1.6 Seeking Additional Help
1.7 Test Taking
1
1
2
4
5
5
5
Chapter 2 – Fundamentals
6
2.1 Introduction
2.2. Atomic Properties
2.2.a. Atoms and the Periodic Table
2.2.b. The Pauli Exclusion Principle and Hund’s Rule – Attraction Between Electrons
2.2.c. Lewis Symbols – Depiction of Valence Electrons
2.2.d. Electronegativity – Attraction Between Atoms and Electrons
2.3 Bonding Theories
2.3.a. VSEPR
2.3.b. Valence Bond Theory
2.3.c. Hybridization
2.3.d. MO Theory
2.4 Types of Bonds and Compounds
2.4.a. Ionic Bonds
2.4.b. Polar Covalent Bonds
2.4.c. Covalent Bonds
2.5 Summary
Solved Problems
6
6
19
19
Chapter 3 – Drawing Chemical Structures
23
3.1 Formal Charges and Electron Dot Structures – A Form of Electronic Bookkeeping
3.2 Kekulé (Line-Bond) and Skeletal Structures of sp3 Hybridized Molecules
3.3 Newman Projections
3.4 Skeletal Structures of Cyclohexanes
3.5 Summary
Solved Problems
23
23
26
27
29
30
Chapter 4 – Stability of Carbon Compounds and Reactive Intermediates
31
4.1 Alkane Stability
4.1.a. Acyclic (non-cyclic) Alkanes
4.1.b. Cyclic Alkanes
4.1.c. Conformational Analysis of Substituted Cyclohexanes
4.2 Alkene Stability
4.2.a. Rigidity of the Double Bond
4.2.b. Steric Consequences
4.2.c. Hybridization Consequences
4.2.d. Hyperconjugation Consequences
4.3 Stability of Aromatic Compounds
4.3.a. The Uniqueness of Benzene
4.3.b. The Resonance Energy of Benzene
31
9
16
39
41
Table of Contents
_____ Chapter Topic__________________________________________________
Page___
4.4 Carbocation Stability
4.4.a. Simple Carbocations
4.4.b. Resonance Stabilized Carbocations
4.5 Stability of Carbon Radicals
4.6 Stability of Carbanions
4.7 Summary
Solved Problems
43
45
47
48
49
Chapter 5 – Isomerism and Stereochemistry
52
5.1 Types of Isomerism
5.1.a. Constitutional Isomerism
5.1.b. Stereoisomerism
5.2 Handedness and Chiral Molecules
5.3 Optical Activity
5.4 The Cahn-Ingold-Prelog (C-I-P) System: Establishing Priorities
5.5 Configuration of Alkenes: cis/trans or E/Z
5.6 Absolute Configuration of Stereoisomers Other Than Alkenes: the R/S Convention
5.7 Fischer Projections
5.8 Meso Compounds
5.9 Haworth Projections
Solved Problems
52
53
54
55
56
57
58
60
60
61
Chapter 6 - Function of Reagents in Organic Chemistry
64
6.1 Acids and Electrophiles
6.2 Bases and Nucleophiles
6.3 Summary
Solved Problems
64
65
66
66
Chapter 7 – Step-by-Step: How Reactions Occur
68
7.1 Acid-Base Reactions/Proton Transfers
7.2 Alkene Additions
7.3 Nucleophilic Substitutions: SN2 and SN1 Reactions
7.3.a. The Bimolecular SN2 Process
7.3.b. The Unimolecular SN1 Process
7.4 Eliminations: E2 and E1 Reactions
7.4.a. The Bimolecular E2 Process
7.4.b. The Unimolecular E1 Process
7.5 Competition Between Nucleophilic Substitutions and Eliminations
7.6 Electrophilic Aromatic Substitution
7.6.a. Bromination of Benzene
7.6.b. Nitration of Benzene
7.6.c. Friedel-Krafts Alkylation of Benzene
7.6.d. Directing Ability of Substituents on the Benzene Ring
7.6.e. Competition Between Directing Groups: Preparation of Trisubstituted Aromatic
Molecules
7.7 Nucleophilic Addition to Carbonyls and Nucleophilic Acyl Substitutions
7.7.a. Reactivity of Carbonyl Species Towards Nucleophilic Attack
7.7.b. Nucleophilic Addition to Carbonyls and Nucleophilic Acyl Substitution
7.7.c. Reduction of Esters: A Double-Barrel Reaction: Nucleophilic Acyl
Substitution and Nucleophilic Addition to a Carbonyl
7.7.d. Carbonyl Analogs
68
70
73
78
83
85
93
Table of Contents
_____ Chapter Topic__________________________________________________
Page___
7.8 Carbonyl Nucleophiles: α - Substitution Reactions
7.8.a. α – Halogenation
7.8.b. α – Alkylation
7.8.c. Carbonyl Condensations
7.9 The Stork Reaction: Enamine Addition to α,β-Unsaturated Carbonyls
7.10 Oxidation of Alcohols with Cr[VI] Reagents
7.11 Summary
Solved Problems
102
106
107
110
110
Appendix A - Reducing Agents
125
Appendix B - Oxidizing Agents
128
Index of Key Terms
132
Index of Chemical Species
134