ABSTRACT
The problems in this chapter are concerned with reactions where bond making and bond breaking occur in concert, referred to as pericyclic reactions. These reactions can be divided into cycloaddition–cycloreversion, electrocyclic, sigmatropic and cheletropic subgroups. Pericyclic reactions do not generally involve intermediates, and stereochemical integrity is retained and defined by the lowest energy concerted pathway. The reactions obey the principle of conservation of orbital symmetry, as delineated by Woodward and Hoffmann. This principle states that orbital symmetry is conserved in a concerted pericyclic reaction.
