Writing a textbook for any level is always a challenge. In organic chemistry, exciting new discoveries are being made at an ever-increasing pace. The great abundance of organic compounds, their fundamental roles in the chemistry of life and their structural diversity have made their study especially challenging and exciting. Organic chemistry is the largest area of specialization among the various fields of chemistry. The underlying theory of organic chemistry pervades the entire scince. The aim of the present book is to incorporate recent advances in the area of organic chemistry and in particular in the field of reaction mechanisms. A thorough understanding of reaction mechanisms helps a student to appreciate how and why reactants go to products. A conceptual understanding of the mechanisms of organic reactions is necessary without which organic chemistry is chaos, and impossible to learn.
The ideas of functionality and stereochemistry have their origins in the second half of the nineteenth century, and the concepts of bonding and reaction mechanism undoubtedly belong to the present century. The purpose of this book is to develop fundamental ideas rather than focus on the sequential presentation of facts. I believe that students benefit most of all from a book which leads from familiar concepts to unfamiliar ones, not just encouraging them to know but to understand and to realize why. I have emphasized the two most important kinds of chemistry that exist — the chemistry that is known as life, and the chemistry that is practised by chemists, solving real problems in laboratories.
Chemists present chemistry in terms of structural diagrams and for this reasons all reactions have been drawn using curly arrows — the handwriting of chemistry. The mechanisms presented are easy to understand and learn as well as interesting and appealing. Each chapter contains only those topics and reactions that are needed to understand the intellectual roots of organic chemistry as it is currently practised. Specific examples are included at each stage to illustrate the mechanism under discussion.
In attempting to accomplish these objectives, my approach is substantially different from that in currently available titles. I hope that students will enjoy and benefit from the experience of learning reaction mechanisms as it is presented in this book. Many examples have been included in each chapter. Theory, mechanism, synthesis, structure and stereochemistry are discussed throughout the book in a qualitative to semi-quantitative fashion.
I have tried to give equal weight to the three fundamental aspects of the study of organic chemistry — reactions, mechanisms and structure. The organization is based on reaction types, so that the students can understand the large number of organic reactions based on relatively few principles. Accordingly, this book is divided into 12 chapters. Each chapter starts with Learning Objectives so that students can understand where they are headed in the chapter. Chapters 1 and 2 discuss the concept of acids and bases, and delocalized chemical bonding and electronic effects. The student is told why these will be important in the study of organic chemistry. Chapter 10 discusses fullerenes and Chapter 12 focuses on aromaticity and aromatic stabilization. The other chapters discuss specific mechanistic types, including nucleophilic substitution, addition reactions, eliminations, aromatic substitution, free-radical reactions, molecular rearrangements, pericyclic reactions and stereochemistry. Each chapter deals with a different type of reaction; the scope and the mechanism of each reaction are discussed.
The problems at the end of each chapter represent the application of concepts to new structures and circumstances, rather than a review of material explicitly presented in the text. They are designed such that the students can test themselves on the material covered before going to the next section. I hope the level of difficulty will present a considerable challenge to students. However, none of the problems are so difficult that the student will lose confidence.
I shall greatly appreciate comments and suggestions from readers which can improve the text or correct errors. I hope that they will enjoy using this text as much as I have enjoyed writing it.