A @C01033@ in which @C01234@ reorganization of bonding takes place throughout a cyclic array of continuously bonded atoms. It may be viewed as a reaction proceeding through a fully @C01267@ cyclic @T06468@. The number of atoms in the cyclic array is usually six, but other numbers are also possible. The term embraces a variety of processes, including @C01496@, @C01014@, @E01948@, @S05660@, etc. (provided they are concerted).