A formalism for the classification and design of organic reactions. I. The class of (− +)nreactions
J. F. Arens · Recueil des Travaux Chimiques des Pays-Bas · 1979
Abstract A coding system for the classification of organic reactions is proposed. The reacting atoms are considered as points on a cycle and the bonds between these points are indicated by 1, 2, 3 or 0 meaning a single, double, triple or no bond respectively. These bonds change during the reaction. The present paper deals with reactions where the number of points is even and where the reaction changes the bonds in a regular fashion, alternatively diminishing or increasing the bond order with one unit. This class of reactions is denoted as reactions with operator (−+)n. Many reactions of great synthetic utility belong to this class.