Synthesis of allylic trifluoromethyl ketones and their activity as inhibitors of the sex pheromone of the leopard moth, Zeuzera pyrina L. (Lepidoptera: Cossidae)

Abstract

An efficient synthesis of allylic TFMKs is reported, with good overall yield, regiospecificity and diastereoselectivity. These compounds are good inhibitors of the pheromone in electrophysiology, wind tunnel and field tests. The results show the importance of two unsaturations at positions 2 and 13 of the trifluoroacyl group in the structure of the analogues, the latter being critical for inhibitory activity.

Inhibition of the Responses to Sex Pheromone of the Fall Armyworm,Spodoptera frugiperda

“…Dissimilar results were obtained in 1:1 and 0.1:1 inhibitor:pheromone mixtures, because whereas the former formulation displayed an antagonist effect, the latter was apparently synergist, but in neither case were the results significant. Overall, these results agree with those previously reported on S. nonagrioides (Riba et al 2001), O. nubilalis (Riba et al 2005; Solé et al 2008a), Cydia pomonella (Giner et al 2009), and Zeuzera pyrina (Muñoz et al 2011), emphasizing the potential utilization of these compounds in pest control. Moreover, the low toxicity displayed by TFMKs has been noticed on Swiss mice (Ashour and Hammock 1987; Riba et al 2001) and in aquatic toxicity studies on algae growth and survival (Rosa et al 2006).…”

Plant volatiles challenge inhibition by structural analogs of the sex pheromone in Lobesia botrana (Lepidoptera: Tortricidae)

“…In the processionary moth T. pityocampa, a structural TFMK analog, in which the acetate group of the pheromone was replaced by the CH 2 COCF 3 group, a 5% blend with the pheromone decreased the close approach and source contact behaviour (Quero et al, 1995). The effect exerted by TFMK analogs was also evident when they were present in the proximity (1 cm apart) of a calling female of the leopard moth Zeuzera pyrina (L.) with 1 μg being suffi cient to induce a highly erratic male fl ight to the source (Muñoz et al, 2011). With regard to the effect of MK analogs on behavioural responses, contradictory reports have appeared in the literature.…”

“…Among the structural analogs, methyl ketones (MKs) and, particularly, trifl uoromethyl ketones (TFMKs), in which the acetate group has been replaced by CH 3 CO or CF 3 CO, respectively, are good disruptants of pheromone perception in a number of lepidopteran species, such as Spodo ptera littoralis Boisduval (Duran et al, 1993;Rosell et al, 1996), Plutella xylostella (L.) (Prestwich & Streinz, 1988), Thaumetopoea pityocampa Denis & Schiffermüller (Parrilla & Guerrero, 1994), Sesamia nonagrioides (Lefevbre) (Bau et al, 1999;Riba et al, 2001), Mamestra brassicae (L.) (Renou et al, 1997), Ostrinia nubilalis (Hübner) (Riba et al, 2005), Bombyx mori (L.) (Pophof et al, 2000), Antheraea polyphemus (Cramer) (Vogt et al, 1985), Cydia pomonella (L.) (Giner et al, 2009), Zeuzera pyrina (L.) (Muñoz et al, 2011), Spodoptera frugiperda Smith (Malo et al, 2013) and Tuta absoluta (Meyrick) (Dominguez et al, 2016). In the fi eld, these chemicals induce a signifi cant Plant volatiles challenge inhibition by structural analogs of the sex pheromone in Lobesia botrana (Lepidoptera: Tortricidae) INTRODUCTION Pheromones are an important element in integrated pest management (IPM) programs, where many insect pests are successfully monitored and controlled by mass trapping and/or mating disruption (Witzgall et al, 2010).…”

Electrophilic derivatives antagonise pheromone attraction inCydia pomonella

“…These chemicals are potent pheromone antagonists of a number of lepidopteran pests, i.e. Spodoptera littoralis Boisduval, Sesamia nonagrioides Lefevre, Ostrinia nubilalis Hübner, CM, Antheraea polyphemus Cramer and A. pernyi Guérin‐Méneville and Zeuzera pyrina L . In electrophysiological tests, these compounds reduced responses to the pheromone, and in a wind tunnel, TFMKs structurally similar to the major component of the pheromone disrupted male orientation to the pheromone .…”

“…In electrophysiological tests, these compounds reduced responses to the pheromone, and in a wind tunnel, TFMKs structurally similar to the major component of the pheromone disrupted male orientation to the pheromone . In the field, blends of these chemicals with the pheromone elicited a marked decrease in male catches in comparison with the pheromone alone . TFMKs are also able to inhibit a variety of esterases and proteases, including pheromone‐degrading enzymes (PDEs) present in insect olfactory tissues .…”