Thermal Electrocyclic Reactions explores the applications of thermal electrocyclic reactions to stereospecific synthesis. This book is divided into nine chapters, and begins with a presentation of the theory of electrocylic reactions using orbital conversions through symmetry operations and correlation diagrams. Considerable chapters are devoted to various conjugate systems entering an electrocyclic process, including two-electron, four electron-three-, four-, and five-atom, and six electron-five-, and six-atom systems. The remaining chapters examine the electrocyclic reaction of longer systems, including eight or more π electrons, as well as conjugated systems with an odd number of electrons, which constitute a special case in the conservation of orbital symmetry. This book will be of great value to organic chemists and researchers.