The pheromone system of the male danaine butterfly, Idea leuconoe

Male Idea leuconoe butterflies release a complex mixture of volatiles from their pheromone glands (hairpencils) during courtship. The pheromone components geranyl methyl thioether (2), viridifloric beta-lactone (3) and 6-hydroxy-4-dodecanolide (10) have been synthesized for the first time. Therefore, the structural assignment of these new natural products could be proved. Related 7-hydroxy-5-alkanoides are also present in the extract. The volatiles are embedded in a lipidic, matrix with more than 150 components. This matrix consists of alkanes, alkenes, 2,5-dialkyltetrahydrofurans, secondary alkanols and alkenols as well as alkanones and alkenones. Several regioisomers of the oxidized hydrocarbons occur. The elucidation of double bond positions has been performed by MS using DMDS adducts.