Organophosphorus compounds. Part 43. A molecular mechanics study: the structural effect of cyclic esters of phosphorus-based acids in hydrolytic reaction

Abstract

Hydrolytic reactions of some cyclic esters of alkylphosphates and phosphonates have been studied using molecular mechanics calculations (Allinger 1977 force field, MM2 1985 program). Either the ratio of the ring opening and retention products, of hydrolysis of five-membered cyclic esters of alkylphosphates and alkylphosphonates or the structural effect of ring size and the endo-ring substituent on the hydrolytic rate constant (k) can be determined from the steric energy difference between the substrate and its pentaco-ordinated transition state (ΔE or ΔΔE). ΔE and ΔΔE can be evaluated by the method of molecular mechanics calculations MM2 1985.