IDENTIFICATION AND SYNTHESIS OF VESPERAL, THE FEMALE SEX-PHEROMONE OFTHE LONGHORN BEETLE VESPERUS-XATARTI

10-Oxoisopiperitenone and 10-hydroxyisopiperitenone (for which the tri vial names vesperal and vesperol are proposed) were identified using v arious EIMS (or MS-MS), CIMS data and GC-Fourier transform infrared ob tained from the female-specific semiochemicals of the longhorn beetle Vesperus xatarti. Their structure was confirmed by synthesis via a Die ls-Alder reaction and appropriate oxidation steps. The role of the fem ale sex pheromone for vesperal was demonstrated. Comparison of the HPL C retention time of natural vesperal with those of synthesized pure en antiomers revealed that the natural compound has (S)-stereochemistry.