Synthesis and insect attractant activity of fluorine-containing Pinus diterpenic amides and imines

A series of fluorine-containing Pinus diterpenic amides and imines have been synthesised and their structures were confirmed by elemental analysis, IR, 1H NMR spectroscopy and single crystal X-ray diffraction. Their insect attractant activity to Spodoptera litura were screened by leaf plate method; the results indicated that most fluorine-containing dehydroabietic amides and imines exhibited attractive activity to S. litura, in which dehydroabietic p-trifluoromethyl amide (A6) exhibit seven times the attractive rate compared with blank at the concentration of 0.01 g mL-1. The fluorine moiety fused to the benzene ring results in decreased attractive rates for amides except (A6), while the effects of fluorine result in increased attractive rates for diterpenic imines.