Simple syntheses of malathion and malaoxon enantiomers, and isomalathion diastereoisomers: toxicity-configuration relationship

Malathion enantiomers were synthesized by nucleophilic substitution of O,O-dimethyl dithiophosphoryl anion to diethyl (R)- or (S)-2-bromosuccinate. Malaoxon enantiomers were obtained from optically active malathions in thiono–thiolo rearrangement with 65% HNO3. Desmethylation of malathion enantiomers by triethylamine, following the remethylation using methyl iodide gave isomalathion diastereomeric pairs. Physicochemical characteristics of the compounds obtained, and their influence on rats and some species of arthropods, are presented.