title: Total Synthesis, Stereochemical Assignment, and Field-Testing of the Sex Pheromone of the Strepsipteran Xenos peckii.
abstract: The sex pheromone of the endoparasitoid insect Xenos peckii (Strepsiptera: Xenidae) was recently identified as (7E,11E)-3,5,9,11-tetramethyl-7,11-tridecadienal. Herein we report the asymmetric synthesis of three candidate stereostructures for this pheromone using a synthetic strategy that relies on an sp(3) -sp(2) Suzuki-Miyaura coupling to construct the correctly configured C7-alkene function. Comparison of (1) H NMR spectra derived from the candidate stereostructures to that of the natural sex pheromone indicated a relative configuration of (3R*,5S*,9R*). Chiral gas chromatographic (GC) analyses of these compounds supported an assignment of (3R,5S,9R) for the natural product. Furthermore, in a 16-replicate field experiment, traps baited with the synthetic (3R,5S,9R)-enantiomer alone or in combination with the (3S,5R,9S)-enantiomer captured 23 and 18 X. peckii males, respectively (mean±SE: 1.4±0.33 and 1.1±0.39), whereas traps baited with the synthetic (3S,5R,9S)-enantiomer or a solvent control yielded no captures of males. These strong field trapping data, in combination with spectroscopic and chiral GC data, unambiguously demonstrate that (3R,5S,9R,7E,11E)-3,5,9,11-tetramethyl-7,11-tridecadienal is the X. peckii sex pheromone.
authors.affiliation: Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhai
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
authors.forename: Michael
authors.initials: M
authors.lastname: Hrabar
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada.
authors.forename: Regine
authors.initials: R
authors.lastname: Gries
authors.affiliation: Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada. gries@sfu.ca.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Gries
authors.affiliation: Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, V5A 1S6, Canada. rbritton@sfu.ca.
authors.forename: Robert
authors.initials: R
authors.lastname: Britton
mesh_terms: D000447:Aldehydes / Q000737:chemistry*; D000818:Animals; D008401:Gas Chromatography-Mass Spectrometry; D007313:Insecta / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010675:Pheromones / Q000138:chemical synthesis* / Q000737:chemistry; D012724:Sex Attractants / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: C000611362:3,5,9,11-tetramethyl-7,11-tridecadienal; D000447:Aldehydes; D010675:Pheromones; D012724:Sex Attractants
keywords: Suzuki-Miyaura; Xenos peckii; insect pheromone; natural products; stereochemical assignment