Organic chemistry is a vibrant and growing scientific discipline that touches a vast number of scientific areas. This first edition of ‘‘The Essence of Pericyclic Reactions’’ has been thoroughly updated to reflect new areas of Organic chemistry, as well as new advances in well-known areas of Organic chemistry. Every topic retained from the fifth edition has been brought up to date. Changes include the

The goal, as in the first edition is to give equal weight to the four fundamental aspects of the study of pericyclic chemistry. A student who has completed a course based on this book should be able to approach the literature directly, with a sound knowledge of modern basic organic chemistry. The organization is based on reaction types, so the student can be shown that despite the large number of organic reactions, a relatively few principles suffice to explain nearly all of them. 

In treating a subject as broad as the basic type of pericyclic chemistry, it is obviously not possible to cover each topic in great depth. Nor would this be desirable even if possible. Nevertheless, students will often wish to pursue individual topics further. An effort has therefore been made to guide the reader to give a small information which is quite useful to understand the concepts. Furthermore, in a graduate course, students should be encouraged to consult primary sources. 

It has been our experience that students who have completed the first-year courses often have a hazy recollection of the material and greatly profit from a representation of the material if it is organized in a different way. It is hoped that the organization of the based on classical and modern notations and by imparting colour to differentiate each of structure will greatly aid the memory and the understanding. 

This book is probably most valuable as a reasonably up-to-date reference work. Students preparing for qualifying examinations and practicing organic chemists will be find most utilization to cover the topics for understanding the way of modification in pericyclic chemistry.

We would like to acknowledge the contributions of those chemists cited and thanked by Professor Anamik Shah for generous contributions to motivate us to write up the book on this special topic. we thank CambridgeSoft Inc. for providing ChemOffice, with ChemDraw, which was used to prepare all reactions and several structures in this book. 

We encourage those who read and use the first edition to contact me directly with comments, errors, and with publications that might be appropriate for future editions.