SYNTHESIS OF COMPONENTS OF THE SEX PHEROMONE OF THE BAGWORM, Oiketicus kirbyi (LEPIDOPERA: PSYCHIDAE)

Abstract

Pheromones are of fundamental importance in controlling various pests, by attracting insects into traps for their capture and reducing the use of pesticides. The species Oiketicus kirbyi, known as bagworm, is an economically important pest; it is polyphago us and attacks various parts of several crops. Insects defoliate the plant to build their bag and to feed, causing large losses in the production of the different crops attacked, such as in oil palm plantations in tropical Americas and mainly in eucalyptus plantations. In this species, the male becomes a moth upon reaching adulthood, the female remains caterpillar-shaped, passing the whole life cycle inside a tough cocoon, made from pieces of leaves, stems, branches, flowers and fruits, that the caterpillar collects, and helps it survive, protecting it from attack of natural enemies and chemical control methods. In this context, the search for sustainable alternatives to control this pest is extremely important. The sexual pheromones of O. kirbyi, already described in the literature, are: methyl butyl octanoate; methyl butyl nonanoate; methyl butyl decanoate; methyl pentyl decanoate; and methyl butyl dodecanoate. Thus, the objective of this work is to synthesize these compounds through Steglish esterification reactions, with secondary alcohols, carboxylic acids, DCC (dicyclohexylcarbodiimide) and DMAP (4-dimethylaminopyridine). The product s obtained were analyzed by hyphenated Gas Chromatography with mass spectrometry (GC/MS) and nuclear magnetic resonance (NMR) spectrometry of hydrogen1H and carbon 13C. Products show fragmentation patterns and characteristic signals of long chain branched esters. Even though they are sterically hindered esters, reactions occurred efficiently, with yields ranging from 70% to 90%.