A simple and sustainable synthetic lab-protocol for obtaining racemic dominicalure- aggregation pheromone of the grain beetle Rhyzopertha dominica F. (Coleoptera, Bostrichidae)

The pheromones constitute a decisive component in the push-pull strategies for the development of ecologically sustainable agricultural systems, the conservation of stored foods in the human communities and the preventive anti-vectorial control. Due to their specific atractantt action and minimum ecological impact their rational application that minimize the volume and utilization of plaguicides, these substances are applied intensively in plants protection systems and stored products. In Cuba and Ecuador several studies are developing, under ecosustainable conditions, on synthetic feasibility of pheromones and their applicability in the population control of insects, mainly the specie Rhyzopertha dominica which causes severe damages in stored grains and derivatives. Previously reported information details the use of expensive reagents and inert conditions (Ar atmosphere, temperaturas of -20 and –25 ⁰C, tedious workup) for carrying out the synthesis of the aggregation pheromone of this specie. Using propionic and isobutiric aldehydes as starting substrates were synthesized, by means of aldolic condensation, selective oxidation with Ag₂O-methanol of monoenic aldehydes, treatment with SOCl₂ and esterificatión with 2-pentanol, the respective components of the racemic aggregation pheromone of this species were synthesized. The NMR ¹H-¹³C structural analysis is detailed for target esters and intermediates, and an attempt of oxidation with TEMPO derivatives is also shown.