ENANTIOMERS OF CIS-3-(4-PROPYL-CYCLOPENT-2-ENYL)PROPYL AND TRANS-3-(4-PROPYL-CYCLOPENT-2-ENYL)PROPYL ACETATE - A STUDY ON THE BIOACTIVE CONFORMATION AND CHIRAL RECOGNITION OF A MOTH SEX-PHEROMONE COMPONENT

The enantiomers of cis- and trans-3-(4-propyl-cyclopent-2-enyl) propyl acetate, which are conformationally constrained analogues of (Z)-5-de cenyl acetate (1), a sex pheromone component of the turnip moth, Agrot is segetum, have been synthesized and tested using the electrophysiolo gical single-sensillum technique. The analogues mimic a cisoid and tra nsoid conformation of 1, respectively. In addition, the enantiomers of each of the cis- and trans-isomers are conformationally constrained a nalogues of enantiomeric cisoid and transoid conformations of 1. Thus, the compounds prepared and tested are well suited to investigate the nature of the bioactive conformation of the natural pheromone componen t 1 and the chiral sense of its interaction with the receptor. Electro physiological single-sensillum recordings show that the activity of th e most active cis-isomer, which has a (1S,4R)-configuration, is more t han two orders of magnitude higher than that of the most active trans- isomer. Furthermore, the (1S,4R)-isomer is at least 100 times more act ive than its enantiomer. These results strongly support a previously p roposed cisoid bioactive conformation of 1. Furthermore, the (1S,4R)-c onfiguration of most active stereoisomer identifies the chiral sense o f the interaction between the natural pheromone component 1 and its re ceptor. (C) 1997 Elsevier Science Ltd.