Lactones 5 * . Synthesis of Some Terpenoid Lactones from , - Epoxy Esters

Synthesis of bicyclic [1] and tricyclic [2] terpenoid lactones and the preliminary results of biological tests for their feeding deterrent activity [3] previously were presented. The tests, which were carried out on three storage pest insects: the grain weevil (Sitophilus granarius L.), the confused flour beetle (Tribolium confusum Duv.) and the khapra beetle (Trogoderma granarium Ev.), showed that our lactones are antifeedants of a considerable activity. Total coefficients of deterrence against the species mentioned above determined in the tests described in [4] reach values from 140 to 170. In comparison, the coefficients for the most potent antifeedant, azadirachtin, determined in the same manner, range from 174 to 194 [5]. Encouraged by these results we decided to extend our interest to monocyclic terpenoid lactones. The reason for this arises from our conviction that antifeedants can find widespread application for plant and food protection against insect pests on condition that they are synthetic compounds of simple chemical structure. According to [6–8] there are known plant origin sesquiterpene, diterpene and limonoid type lactones possessing antifeedant activity. There is no information about biological tests carried out for simple terpene lactones. In our opinion, it is worth-while to check the feeding deterrency of this type of compounds. Thus, in this paper we present the synthesis of some ten or eleven carbon atoms hydroxy and -lactones with isoprenoid structure. Polish J. Chem., 74, 673–680 (2000)