SYNTHESIS AND BIOLOGICAL EVALUATION OF NEW PYRETHROIDS HAVING HALOGEN, KETO, OR NITRO GROUP-CONTAINING SUBSTITUENTS

Thirteen pyrethroid esters, most of which contain strong electron-with drawing groups (e.g., halomethylketo and nitro groups) in the side cha in of the cyclopropane acid moiety, have been synthesized. The synthes is involved the reaction of various active methylene compounds with 3- formyl-2,2-dimethylcyclopropanecarboxylic esters of known pyrethroid a lcohols. Rather than the usually employed Wittig reaction for these sy ntheses, the novel pyrethroid acid moieties were prepared by amino aci d-catalyzed Knoevenagel condensations under mild conditions. Prelimina ry toxicity studies of the pyrethroid esters, against several insect a nd one mite species, were conducted. Two of these compounds had good r epellent activity against the twospotted spider mite (Tetranychus urti cae) at 100 ppm, and six of them had medium insecticidal activity agai nst either black bean aphid (Aphis fabae) or western potato leafhopper (Empoasca abrupta) at 10 ppm.