This book provides an introduction to organic photochemistry and the study of electronically excited states of organic molecules for graduate and upper level undergraduate students. This book aims to be useful to synthetic organic chemists who need to learn the rudiments of organic photochemistry and the extensive references make this volume a useful reference for practicing photochemists. The examples used in this book were chosen to appropriately illustrate principles of organic photochemistry and synthetic routes to organic compounds. The author has chosen to present photochemical synthetic methods that have been experimentally checked for accuracy.