Electrochemically synthesized dihydrobenzofurans were evaluated for their insect antifeedant activities against phytophagous insects. They were prepared through the coupling reactions of various alkenes with a phenoxy cation generated by oxidation near the cathode in the electrolytic reaction. The insect antifeedant activities of these synthetic dihydrobenzofurans were evaluated in the common cutworm (Spodoptera litura) and diamond back moth (Plutella xylostella) with the dual choice leaf disk bioassay method. The insect antifeedant activities of most of the acetophenone-type dihydrobenzofurans were strong, while those of derivatives with a t-butyl group were weaker. The biological activities in insect species differed with the structural features of the compounds.
Keywords: dihydrobenzofuran; electrochemical synthesis; insect antifeedant.