Simulation of Irreversible Cyclization of Bifunctional Chains. A Computer-aided Approach to the Synthesis of Many-membered Rings and to the Evaluation of Effective Molarities by Preparative Experiments

Two complementary kinetic models for the reaction of a bifunctional reactant A-B to give macrocycles under either batch-wise or influxion (Ziegler high dilution) conditions, are described. The degree of accuracy of both models is variable at will, depending on the value of the maximum polymerization degree accounted for by the models themselves. On the basis of these models, a computer program (CYCLES) has been developed, serving both as an useful tool for the optimization of reaction conditions in the synthesis of many-membered rings, and as the essential means of obtaining effective molarities by preparative experiments. The program CYCLES performs fourth-order Runge-Kutta numerical integration of the set of differential rate equations pertinent to each kinetic model for an arbitrary value of the degree of polymerization.