Eto_1983_J.Environ.Sci.Health.B_18_119

Chemical and biochemical studies on three types of cyclic phosphoryl compounds are discussed in connection with the development of insecticides. They are five-membered cyclic phosphoramidates (I), six-membered cyclic phosphates (II) and bridged bicyclic phosphates (III). Development of I has started from the finding of L-leucine as a neuroactive substance in silkworm blood, followed by its combination with chemically active five-membered cyclic phosphates. Studies on the metabolism of neurotoxic tri-o-tolyl phosphate caused the invention of the insecticide salithion in the series of II. Salithion was chemically converted into its thiolo isomers, which is a convenient phosphorylating agent useful to synthesize biologically interesting phosphate esters. III does not inhibit acetylcholin-esterase but acts as an anti-GABA agent.