STEREOCHEMICAL EVIDENCE OF DUAL CHEMORECEPTORS FOR AN ACHIRAL SEX-PHEROMONE IN LEPIDOPTERA

The racemate and optically pure enantiomers of 9-(cyclopent-2-en-l-yl)nonyl acetate have been synthesized and found to mimic certain biological properties of a natural sex pheromone, (Z)-11-tetradecenyl acetate. European corn borer and redbanded leaf rollers respond differently to the racemate and to the enantiomers in precopulatory-behavior bioassay. The bioassay results demonstrate the presence of two stereospecific chemoreceptors for the achiral pheromone and the chiral character of these chemoreceptors, and define the conformation of carbon atoms 10-14 of (Z)-11-tetradecenyl acetate in each receptor. Specificity in communication is the adaptive advantage the insect gains by using two stereospecific chemoreceptors with different conformational requirements for the achiral pheromone. The methodology described provides a new tool for neurochemical investigation of chemical sensing. A correlation of specific rotation and molecular weight is demonstrated for 3-substituted cyclopentenes. Optically active aleprolic acid, the parent acid of the chaulmoogric acid series, has been synthesized and fully characterized. © 1978, American Chemical Society. All rights reserved.