Synthesis of the acids structurally related to tetramethylcyclopropanecarboxylic acid and their esters.

Abstract

One of us and a co-worker discovered that a simple compound, the allethronyl ester of 2,2,3,3-tetramethylcyclopropanecarboxylic acid (I)1*, had the equal or higher insecticidal activity to those of chrysanthemic esters, and also that 2,2-dichloro-3,3-dimethylcyclopropanecarboxylic acid ( 2) esters2) had a half or less order of activity. On the other hand, Elliott et al.3) found that the acyano-3-phenoxybenzyl ester of 2,2-dimethyl-3(2,2dibromovinyl)cyclopropanecarboxylic acid (3, decamethrin), was the most active pyrethroid insecticide. So it is interesting to investigate the synthesis and insecticidal activity of 2,2-dibromo-3,3-dimethylcyclopropanecarboxylic acid (4) ester, acid 3 corresponding to a vinylogue of acid 4. Meanwhile, Miyakado et al.A) reported that aisopropyl(4-chlorophenyl)acetic acid, the acid moiety of a pyrethroid (fenvalerate),resembled in steric structure that of chrysanthemic acid. Therefore, it is also interesing to examine the activities of esters of bicyclo [2,2,l]heptenecarboxylic acids (5 and 6), these acids seeming to be similar to the acid 1 in steric structure.