Analogues of antijuvenile hormones

Abstract

Several analogues of precocenes I and II have been synthesized, including derivatives of 6,7-dihydroxy-2,2-dimethylchromen, 7,8-dihydroxy-2,2-dimethylchromen, 7-hydroxy-2,2-dimethyl-6-nitrochromen, and 6-amino-7-hydroxy-2,2-dimethylchromen. 5,6-Dimethoxy-3,3-dimethylindene was also synthesized. Improved procedures for the dehydration of chroman-4-ols to chromens and for the reduction of chroman-4-ones to chroman-4-ols are reported. Analogues have been tested for activity in the brown planthopper Nilaparvatus lugens Stal. None had significant morphogenetic effects, but two possessed insecticidal activity and showed both antagonism and synergism when used in conjunction with permethrin.