title: Electrophilic derivatives antagonise pheromone attraction in Cydia pomonella.
abstract: BACKGROUND
  Pheromone antagonists are good disruptants of the pheromone communication in insects and, as such, have been used in mating disruption experiments. In this study, new non-fluorinated electrophilic keto derivatives structurally related to the pheromone of Cydia pomonella (codlemone) have been synthesised and tested as putative pheromone antagonists.
  
  
  RESULTS
  Codlemone (1) was prepared in excellent stereoselectivity in a new, iterative approach involving two Horner-Wadsworth-Emmons reactions. Methyl ketone (2), keto ester (3) and diketone (4) were obtained from codlemone in straightforward approaches in good overall yields and excellent stereochemical purity (≥98% E,E). In electrophysiology, only compound 2 displayed inhibition of the antennal response to the pheromone after presaturation of the antennal receptors. Compounds 2 to 4 did not inhibit the pheromone-degrading enzyme responsible for codlemone metabolism, but mixtures of ketone 2 and diketone 4 with codlemone elicited erratic flights on males in a wind tunnel. In the field, blends of either compound (2 or 4) with the pheromone caught significantly fewer males than codlemone alone.
  
  
  CONCLUSIONS
  Codlemone and the potential antagonists 2 to 4 have been synthesised in good yields and excellent stereoselectivity. These chemicals behave as pheromone antagonists of the codling moth both in the laboratory and in the field.
authors.affiliation: University of Lleida, Centre UdL-IRTA, Lleida, Spain.
authors.forename: Albert
authors.initials: A
authors.lastname: Sans
authors.forename: Rafael
authors.initials: R
authors.lastname: Gago
authors.forename: Ares
authors.initials: A
authors.lastname: Mingot
authors.forename: Wanda
authors.initials: W
authors.lastname: García
authors.forename: Dolors
authors.initials: D
authors.lastname: Bosch
authors.forename: Josep
authors.initials: J
authors.lastname: Coll
authors.forename: Gloria
authors.initials: G
authors.lastname: Rosell
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Bosch
authors.forename: Magí
authors.initials: M
authors.lastname: Riba
authors.forename: Angel
authors.initials: A
authors.lastname: Guerrero
mesh_terms: D000818:Animals; D007851:Dodecanol / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D008297:Male; D009036:Moths / Q000187:drug effects* / Q000502:physiology*; D012724:Sex Attractants / Q000037:antagonists & inhibitors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D012724:Sex Attractants; D007851:Dodecanol; C001977:8,10-dodecadien-1-ol
keywords: Cydia pomonella; codling moth; pest control; pheromone analogues; pheromone antagonists