Organic Chemistry: An Intermediate Text - Hardcover

Hoffman, Robert V.

Hardcover

ISBN 10: 0471450243 ISBN 13: 9780471450245

Publisher: Wiley-Interscience, 2004

Synopsis

Ideal for those who have previously studies organic chemistry but not in great depth and with little exposure to organic chemistry in a formal sense. This text aims to bridge the gap between introductory-level instruction and more advanced graduate-level texts, reviewing the basics as well as presenting the more advanced ideas that are currently of importance in organic chemistry.
* Provides students with the organic chemistry background required to succeed in advanced courses.
* Practice problems included at the end of each chapter.

About this title

About the Author

ROBERT V. HOFFMAN, PhD, is Professor Emeritus of Chemistry at New Mexico State University in Las Cruces, New Mexico.

From the Back Cover

A foundation for success in advanced organic chemistry courses and careers

Graduate students taking advanced organic chemistry courses often need a refresher on the discipline before they can move on to more specialized topics. This is especially true of students whose last formal exposure to organic chemistry was during their undergraduate studies. Organic Chemistry: An Intermediate Text bridges this gap, reacquainting students with basic organic chemistry while introducing them to the most important advanced topics in the field today.

The book presents a principles-focused discussion of organic chemistry from a unique mechanistic and structural perspective. Beginning with the classification of functional groups by bonding patterns and oxidation levels, it describes general mechanistic considerations vital to the understanding of functional group transformations from electron movement to stereoelectronic effects. Building on this mechanistic framework, the text then provides insight into synthetic transformations commonly employed in modern organic chemistry.

Updated and revised throughout, the Second Edition of Organic Chemistry: An Intermediate Text features:

• A stronger emphasis on mechanisms
• An expanded overview of resonance and aromaticity
• A new section on uses of organopalladium chemistry and olefin metathesis in carbon-carbon bond formation
• A revised examination of free radical reactions for carbon-carbon bond formation
• A fuller discussion of Diels-Alder chemistry

Chapter-ending problems, many of which are new to this edition, help to reinforce pivotal concepts required to fully comprehend the text material. This book is illustrated with abundant structures and figures that demonstrate these concepts.

Graduate students taking advanced organic chemistry courses often need a refresher on the discipline before they can move on to more specialized topics. This is especially true of students whose last formal exposure to organic chemistry was during their undergraduate studies. Organic Chemistry: An Intermediate Text bridges this gap, reacquainting students with basic organic chemistry while introducing them to the most important advanced topics in the field today.

The book presents a principles-focused discussion of organic chemistry from a unique mechanistic and structural perspective. Beginning with the classification of functional groups by bonding patterns and oxidation levels, it describes general mechanistic considerations vital to the understanding of functional group transformations–from electron movement to stereoelectronic effects. Building on this mechanistic framework, the text then provides insight into synthetic transformations commonly employed in modern organic chemistry.

Updated and revised throughout, the Second Edition of Organic Chemistry: An Intermediate Text features:

• A stronger emphasis on mechanisms
• An expanded overview of resonance and aromaticity
• A new section on uses of organopalladium chemistry and olefin metathesis in carbon-carbon bond formation
• A revised examination of free radical reactions for carbon-carbon bond formation
• A fuller discussion of Diels-Alder chemistry

Chapter-ending problems, many of which are new to this edition, help to reinforce pivotal concepts required to fully comprehend the text material. This book is illustrated with abundant structures and figures that demonstrate these concepts.

Excerpt. © Reprinted by permission. All rights reserved.

Organic Chemistry

An Intermediate TextBy Robert V. Hoffman

John Wiley & Sons

Copyright © 2004 John Wiley & Sons, Inc.
All right reserved.
ISBN: 978-0-471-45024-5

Contents

Preface.................................................................................................xiiiPreface to the First Edition............................................................................xv1 Functional Groups and Chemical Bonding................................................................1Functional Groups.......................................................................................1Orbitals................................................................................................5Bonding Schemes.........................................................................................7Antibonding Orbitals....................................................................................13Resonance...............................................................................................18Conjugated [pi] Systems.................................................................................21Aromaticity.............................................................................................23Bibliography............................................................................................26Problems................................................................................................272 Oxidation States of Organic Compounds.................................................................32Oxidation Levels........................................................................................32Oxidation States in Alkanes.............................................................................34Oxidation States in Alkenes.............................................................................34Oxidation States in Common Functional Groups............................................................35Oxidation Level Changes During Reactions................................................................35Bibliography............................................................................................41Problems................................................................................................413 Acidity and Basicity..................................................................................47Bronsted and Lewis Acids and Bases......................................................................47Acid Strength...........................................................................................49Acid-Base Equilibria....................................................................................53Amphoteric Compounds....................................................................................56Structural Effects on Acidity...........................................................................56Bibliography............................................................................................63Problems................................................................................................634 Curved-Arrow Notation.................................................................................69Electron Movement.......................................................................................69Heterolytic Bond Cleavages..............................................................................70Heterolytic Bond Formation..............................................................................71Homolytic Bond Making and Bond Breaking.................................................................73Resonance Structure.....................................................................................75Depiction of Mechanism..................................................................................76Bibliography............................................................................................82Problems................................................................................................825 Mechanisms of Organic Reactions.......................................................................86Activation Energy.......................................................................................87Activated Complex.......................................................................................88Reaction Energetics.....................................................................................89Structure of the Activated Complex......................................................................91Hammond Postulate.......................................................................................96Reaction Kinetics.......................................................................................99Determining Activation Energies.........................................................................104Isotope Effects.........................................................................................105Electronic Effects......................................................................................110Hammett Equation........................................................................................111Bibliography............................................................................................118Problems................................................................................................1186 Stereochemical and Conformational Isomerism...........................................................124Stereochemical Structures...............................................................................125Chirality...............................................................................................128Configuration of Chiral Centers.........................................................................129Multiple Stereocenters..................................................................................132Optical Activity........................................................................................137Absolute Configuration..................................................................................138Physical Properties of Enantiomers......................................................................139Resolution of Enantiomers...............................................................................140Stereoselective Reactions...............................................................................144Formation of Enantiomers................................................................................144Formation of Diastereomers..............................................................................146Stereochemistry to Deduce Mechanism.....................................................................152Conformational Analysis.................................................................................157Conformational Energies.................................................................................164A Values................................................................................................166Strain in Ring Systems..................................................................................167Stereoelectronic Effects................................................................................172Bibliography............................................................................................176Problems................................................................................................1767 Functional Group Synthesis............................................................................183Functional Group Manipulation...........................................................................183Carboxylic Acids........................................................................................185Esters..................................................................................................188Amides..................................................................................................190Acid Chlorides..........................................................................................191Aldehydes...............................................................................................192Ketones.................................................................................................194Imines and Imine Derivatives............................................................................197Alcohols................................................................................................198Amines..................................................................................................201Alkenes.................................................................................................203Alkanes.................................................................................................207Bibliography............................................................................................208Problems................................................................................................2098 Carbon-Carbon Bond Formation between Carbon Nucleophiles and Carbon Electrophiles.....................216Synthetic Strategy......................................................................................217Nucleophilic Carbon.....................................................................................218Electrophilic Carbon....................................................................................220Reactivity Matching.....................................................................................223Generation of Nucleophilic Carbon Reagents..............................................................224Generation of Electrophilic Carbon Reagents.............................................................227Matching Nucleophiles with Electrophiles................................................................227Enolates................................................................................................228Enolate Regioisomers....................................................................................234Diastereoselection in Aldol Reactions...................................................................236Organometallic Compounds................................................................................239Neutral Carbon Nucleophiles.............................................................................239C=C Formation...........................................................................................242Cyclopropanation Reactions..............................................................................244Metal-Catalyzed Carbon-Carbon Bond Formation............................................................246Pd(0)-Catalyzed Carbon-Carbon Bond Formation............................................................247Olefin Metathesis.......................................................................................256Bibliography............................................................................................261Problems................................................................................................2629 Carbon-Carbon Bond Formation by Free-Radical Reactions................................................272Free-Radical Reactions..................................................................................272Free-Radical Polymerization.............................................................................277Nonpolymerization Reactions.............................................................................278Free-Radical Initiation.................................................................................280Free-Radical Cyclization................................................................................283Bibliography............................................................................................288Problems................................................................................................28810 Planning Organic Syntheses...........................................................................292Retrosynthetic Analysis.................................................................................292Carbon Skeleton Synthesis...............................................................................296Umpolung Synthons.......................................................................................302Acetylide Nucleophiles..................................................................................305Ring Construction.......................................................................................306Robinson Annulation.....................................................................................310Diels-Alder Reaction....................................................................................312HOMO-LUMO Interactions..................................................................................313Stereoelectronic Factors................................................................................3161,3-Dipolar Cycloadditions..............................................................................319Bibliography............................................................................................323Problems................................................................................................32411 Structure Determination of Organic Compounds.........................................................332Structure Determination.................................................................................332Chromatographic Purification............................................................................333Instrumental Methods....................................................................................335Nuclear Magnetic Resonance..............................................................................336Chemical Shift..........................................................................................338Spin-Spin Coupling......................................................................................344Descriptions of Spin Systems............................................................................350Second-Order Splitting..................................................................................354Structure Identification by 1H NMR......................................................................355Carbon-13 NMR...........................................................................................360Infrared Spectroscopy...................................................................................366IR Stretching Frequencies...............................................................................367Use of IR Spectroscopy for Structure Determination......................................................371Mass Spectrometry.......................................................................................377Fragmentation Processes.................................................................................384Bibliography............................................................................................388Problems................................................................................................388Solutions to Chapter Problems...........................................................................395Index...................................................................................................471

Preface

PREFACE TO THE FIRST EDITION

This text was inspired by two observations. The first is that many entering graduate students took organic chemistry as sophomores but since that time have had little exposure to organic chemistry in a formal sense. Because of this time lapse in their organic preparation, they often have difficulty performing well when placed directly into mainstream graduate level organic courses. What is much more effective is to first place them in a course which will bring them back up to speed in basic organic chemistry and at the same time introduce many of the advanced topics which are crucial to understanding current advances in the field. A course well suited for this purpose is a one-semester, advanced organic course at the senior undergraduate/beginning graduate level. Most departments, including ours, have such a course in place. Textbook selection for this course is problematic, however. If one of the standard advanced texts is used, only a small part is actually covered and students are not prepared to master the complexities, whereas if an undergraduate text is used, it often fails to push the students to the next level. Consequently, there is a real need for a one-semester text which gives a review of basic principles in addition to an exposure to the ideas which are currently of great importance in organic chemistry. This text was written to fill this need.

A second observation instrumental in shaping the approach of this text was made during group discussions of the organic faculty and students. One common exercise is to present practice cumulative exam problems to the group and discuss ways in which they might be solved. It is very common for the students to analyze the question in terms of reactions and transformations and try to arrive at a solution based on the question as written. On the other hand, it is very common for the faculty to ask very simple questions first-for example, "What is the oxidation change?" "What is the p[K.sub.a] of the acid and what is the base?" and "What stereochemical changes occur?" It is clear that more experienced organic chemists begin from a very basic point of view and progress to a more complex solution, whereas novice organic chemists tend to jump in at a much more difficult level. It thus appears very important to initially emphasize the basic principles on which organic chemistry depends and then progress to more specialized topics, all the while emphasizing their relationship to the basic principles. This text utilizes this organizational approach.

The result is a textbook designed for a one-semester advanced organic chemistry course. First and foremost it is a textbook and not a reference text. There is plenty of material to fill a semester, but it is not comprehensive in its coverage. Topics were chosen to provide a basic and well-rounded discussion of ideas important in modern organic chemistry and to provide students with the necessary tools to succeed in more specialized advanced courses. It is a book to be taught from; thus instructors should take the opportunity to include special or favorite topics at appropriate points. References to alternative textbook and literature reviews of the subjects are included so that students can go to the library and get a different explanation. This is important for encouraging students to do library work as a means to independently gain insight and understanding. Finally, there are abundant problems included at the end of each chapter so that students can practice applying what they are learning. Working problems is the single most effective way to learn and organize the large amount of information that is encountered in organic chemistry, so there are a large number of practice problems available at all levels of difficulty.

The goal of this text is to provide senior undergraduate students the organic background required to move on successfully in their careers. For beginning graduate students lacking this background, it provides a succinct yet rigorous preparation for advanced organic courses. R.V.H.

(Continues...)

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Edition details

• Publisher: Wiley-Interscience
• Publication date: 2004
• Language: English
• ISBN 10: 0471450243
• ISBN 13: 9780471450245
• Binding: Hardcover
• Edition number: 2
• Number of pages: 496