Estudo de metodologias de síntese de feromônios para o controle de insetos-praga

Abstract

Growing food efficiently and sustainably is a matter of great relevance and of enormous repercussion in society. A current strategy for crop pest control is the use of synthetic pheromones based on a safe environmental management approach. The present work consists of the synthesis of sex pheromones and candidate molecules for pheromones of the main insect pests of soybean (Chrysodeixis includens), cashew (Anacampsis phytomiella), apple (Bonagota salubricola), coffee (Leucoptera coffeella) and açaí (Ozopherus muricatus). In the proposed synthetic routes to obtain these compounds, couplings with organometallics are explored, such as Grignard and Sonogashira reactions for the formation of carbon-carbon bonds, in addition to bromination, dehydration, hydrogenation, reduction and acetylation reactions. These synthesis methodologies led to the formation of (Z)-7-dodecenyl acetate (C. includens) and 5,9- dimethylpentadecane (L. coffeella) with global yields of 54% and 28%, respectively. Economic and promising synthesis methodologies are proposed to obtain these pheromones. In the synthesis of (3E,5Z)-dodecadienyl acetate (B. salubricola) the key intermediate, (Z)-5-dodecen3-yn-1-ol, was obtained in 53% overall yield. Studies related to the identification of semiochemicals from A. phytomiella and O. muricatus were carried out by the research group, LPqRN, indicating candidate molecules for pheromones from these pests, the (Z)-7,9- decadienyl and (Z)-9,11-dodecadienyl acetates, indicated for A. phytomiella were synthesized with yields of 53% and 59%. For O. muricatus the suggested molecules, 3-nonanone and 3- methylheptane, were obtained with yields of 79% and 59%, respectively. The synthetic routes studied for the preparation of these compounds proved to be applicable and efficient.