Synthesis and biological activity of pyrethroids derived from halo-4-alkenoic acids

• Published in: Journal of agricultural and food chemistry Vol. 31; no. 1; pp. 72 - 85
• Main Authors: Ayad, H M, Wheeler, T N
• Format: Journal Article
• Language: English
• Published: 01.01.1984
• ISSN: 0021-8561

Sixty-two examples of pyrethroids derived from halo-4-alkenoic acids have been synthesized. The halo-4-alkenoic acids were prepared by a modified malonic ester synthesis or by allylation of O-silylated ketene acetals. The pyrethroids derived from halo-4-alkenoic acids bearing an alkyl group at C sub(3) are novel, and the crucial effect of the nature and number of alkyl substituents at C sub(3) on insecticidal activity of the 5,5-dihalo-4-alkenoic esters has not been reported previously. Several of the novel esters exhibit good broad-spectrum insecticidal and some miticidal activity, but the most active of the halo-4-alkenoic esters is considerably less active, particularly on lepidopterous larvae, than commercial pyrethroids.