Synthesis and field testing of enantiomers of 6Z,9Z-cis-3,4-epoxydienes as sex attractants for geometrid moths : Interactions of enantiomers and regioisomers.

Stereoselective syntheses of chiral C17 to C21 6Z,9Z-cis-3,4-epoxydienes were developed. Field tests of the enantiomerically enriched epoxides as components of synthetic sex attractant lures were carried out, and those with C17 and C19 chain lengths, particularly, were attractive to male moths of several species. Moths were usually specifically attracted by one of a pair of enantiomers, and the opposite enantiomer could actually be a behavioral antagonist. Males belonging to nine species of Geometridae were captured.Probole amicaria (Herrich-Schäffer) males were taken in traps baited with the mixture (6Z,9Z,3S,4R)-epoxy-nonadecadiene (6Z,9Z,3S,4R-epoxy-19∶H) + 3Z,9Z,6R,7S-epoxy-19∶H + 3Z,6Z,9Z-19∶H(9∶1∶8). Other species responding to the C19 compounds included (attractant components follow in parentheses);Sicya macularia (Harris) (6Z,9Z,3S,4R-epoxy-19∶H + 3Z,6Z,9Z-19∶H),Anavitrinella pampinaria (Guenée) (6Z,9Z-cis-3,4-epoxy-19∶H + 3Z,9Z,6S,7R-epoxy-19∶H), andLycia ursaria (Walker) (6Z,9Z-3S, 4R-epoxy-19∶H + 3Z,6Z,9Z-19∶H). Males of the following species were captured byC 17 epoxides:Itame occiduaria (Packard) (6Z,9Z,3R,4S-epoxy-17∶H + 3Z,6Z,9Z-17∶H),Itame brunneata (Thunberg) (6Z,9Z,3S,4R-epoxy-17∶H),Epelis truncataria (Walker) (both enantiomers of 6Z,9Z-cis-3,4-epoxy-17∶H),Semiothisa ulsterata (Pearsall) (3Z,9Z-6S,7R-epoxy-17∶H), andS. signaria dispuncta (Walker) (3Z,9Z-cis-6,7-epoxy-17∶H + 3Z,6Z,9Z-17∶H). The interactions among enantiomers and regioisomers are discussed as a mechanism by which cross attraction between sympatric species is limited.