Idea leuconoe pheromone

P" and S-lactones present in the pheromone system of the giant white butterfly, Idea leuconoe, were synthesized. 

Nishida, R Schulz, S., Kim, C. S. et al. (1996). Male sex pheromone of a giant danaine butterfly, Idea leuconoe. Journal of Chemical Ecology 22 949-972. 

Viridifloric /3-lactone, 143, has been identified as one of the pheromone components of a complex mixture of volatiles released by the pheromone glands of the male Idea leuconoe butterfly during courtship <1996BMC341>. A racemic mixture of both diastereoisomers was synthesized in four steps from the dilithio salt of 3-methylbutyric acid 144 alkylation with ethanal, dehydration of the secondary alcohol with phosphorus pentoxide, dihydroxylation of the C-C double bond with osmium tetraoxide, and finally formation of the /3-lactone by cyclization with sulfonyl chloride. By comparison with the sample isolated from I. leuconoe, the absolute configuration was established to be (2V,3V)-2-hydroxy-2-(l-methylethyl)-3-butanolide 143. 

An interesting sidelight on the metabolism of pyrrolizidines is that several butterfly and moth larvae that feed on plants containing these alkaloids metabolize them to products that serve the insects as pheromones or defensive substances. Thus the butterfly Idea leuconoe converts alkaloids from Parsonia laevigata to N-oxides [121]. The moth Creatonotos transiens makes its pheromone, R(-)-hydroxydanaidal from7(S)-heliotrine found in its host plant, Senecio jacobaea [122]. 

A number of male courtship pheromones are known to be synthesized from the necine base moiety of plant-acquired PAs by certain alkaloid sequestering Arctiidae, Danainae, and Ithomiinae [75,96] (Fig. 11). The giant white danaine butterfly Idea leuconoe [97,98] and most ithomiine butterflies even use lactones as pheromones derived from necic acids such as the (-)-viridifloric acid from... 

In 1999, Schulz reported on the synthesis of (S,S)- or (/ ,/f)-6-hydroxyalkan-4-olides, components of the pheromonal secretion of the butterfly Idea leuconoe. The enantioselective hydrogenation reaction of methyl 4,6-... 

---