Reaction Mechanism in Organic Chemistry

The book opens with a chapter on the Chemical Bond which apart from describing the different types of chemical bonds, highlights the importance of the concepts of the electronegativity and effect of the state of hybridization of the bonding orbitals on the physical properties of the molecules. In addition to Hückel's treatment of aromaticity, a new outlook for determining aromaticity and resonance energy has been introduced based on the Perturbational Molecular Orbital (PMO) method developed by M. J. S. Dewar. This chapter coupled with the second and third chapters- which deal with the reaction intermediates, reagents, energies, stereochemical terms and methods for determining reaction mechanisms- form the background materials for the subsequent chapters.

In dealing with the conventional topics such as substitution reactions, addition and elimination reactions, reactions of carbonyl group, free radicals, etc., we have tried to project current developments, wherever possible. The purpose of giving specific examples in these chapters is to illustrate principles rather than giving a review-type coverage. We had to be selective rather than comprehensive because of our anxiety to limit the book to a reasonable size and price.

The last two chapters, namely, Organic Photochemistry and Pericyclic Reactions, have been included due to our conviction that these topics should form an integral part of the course on reaction mechanism in recognition of their growing importance. These topics should also be helpful to those research students whose training in these fascinating areas of organic chemistry was not up to the current standard. In addition to Woodward Hoffmann's orbital correlation method based on the principles of molecular orbital symmetry, and the frontier orbital method, we have discussed in reasonable detail the PMO method for the analysis of pericyclic reactions. This latter method should be particularly welcome to the readers as it offers simple mnemonics of selection rules for prediction of the stereochemical courses of this class of reactions.

Chapter 1: Nature of Bonding in Organic Molecules

Chapter 2: Stereochemistry-I

Chapter 3: Stereochemistry-II

Chapter 4: Organic Reactions, Reagents and Reaction Intermediate

Chapter 5: General Principles and Methods of Determination of Reaction Mechanism

Chapter 6: Aliphatic Nucleophilic Substitution

Chapter 7: Addition to Carbon-Carbon Multiple Bond

Chapter 8: Elimination Reactions

Chapter 9: Reactions of the Carbonyl Group

Chapter 10: Aromatic Electrophilic Substitution

Chapter 11: Aromatic Nucleophilic Substitution

Chapter 12: Molecular Rearrangements

Chapter 13: Free Radicals

Chapter 14: Organic Photochemistry

Chapter 15: Pericyclic Reactions