Chirality of macrolide pheromones of grain beetles in the generaOryzaephilusandCryptolestes and its implications for species specificity

The chiralities of macrolide lactone aggregation pheromones of five species of economically important grain beetles have been determined by capillary gas chromatographic separation of the diastereomeric (S)-O-acetyllactate derivatives of the hydroxy methyl esters derived from boron trifluoride-catalyzed cleavage of the macrolides in methanol. Chirally pure (Z)-3-dodecen-11-olide (I) is produced in theS configuration byCryptolestes ferrugineus (Stephens) and in theR configuration byOryzaephilus mercator (Fauvel). (Z,Z)-3,6-Dodecadien-11-olide (II) is produced in theR configuration by bothO. mercator andO. surinamensis (L.). (Z,Z)-5,8-Tetradecadien-13-olide (IV) is produced in theR configuration byO. surinamensis and as a 8515 mixture ofR andS isomers byC. turcicus. (Z)-5-Tetradecen-13-olide (V) is produced in the S configuration byC. pusillus (Schönherr) and as a 3367 mixture of theR andS isomers byC. turcicus (Grouvelle). The results indicate that in these cucujids, species specificity in pheromone response is maintained at least in part by pheromone chirality.Research supported by the Natural Sciences and Engineering Reseach Council of Canada, Operating Grants A3881, A0851 and A3785, and Strategic Grant G0958.