Synthesis of Allyl Esters of Fatty Acids and Their Ovicidal Effect on Cydia pomonella (L.)

Abstract

Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.

Antennal and Behavioral Response of Cydia pomonella and Lobesia botrana Moths to Allyl Cinnamate

“…Other authors have described a similar synergism to plant volatiles [21,25]. This could be extremely interesting if confirmed in a field situation.…”

“…Moreover, allyl esters can be synthesized from glycerol or fat wastes [21,22], what fosters the re-use of industrial sub products. However, more assays need to be done to fix the proportion of allyl cinnamate into the blend to improve the attractiveness of moths [39,40] and asses it in field conditions, as well as the fate of allyl cinnamate in field conditions.…”

“…Our research group has been working on allyl ester synthesis using glycerol as starting material [21,22], which is produced in large amounts as a by-product in biodiesel production (http://www.biodiesel.org/). The insecticidal properties of some allyl esters have been assessed previously in order to give an added value to the surplus of glycerol [21,23,24].…”

“…The insecticidal properties of some allyl esters have been assessed previously in order to give an added value to the surplus of glycerol [21,23,24]. As several volatile compounds from codling and grapevine moth host-plants are used by adults for host and mate localization [25][26][27][28], an effect in moth behavior due to allyl esters used as fruit aromas [29] was suspected.…”

TOXICITY OF ALLYL ESTERS IN INSECT CELL LINES AND IN SPODOPTERA LITTORALIS LARVAE

“…Essential oils are mainly mixtures of different compounds, some of which belong to the ester chemical group (Daferera et al, 2000;Skaltsa et al, 2003;Bakkali et al, 2008) that had shown insecticidal properties (Ojimelukwe and Adler, 1999;Peterson et al, 2000;Leelaja et al, 2007;Escribà et al, 2009). Moreover, no adverse effects toward human health or the environment are expected because several of these products are already approved for use as fragrances and food flavors (Bauer et al, 2001;Burdock, 2010).…”