Gnatocerus cornutus

The aggregation pheromone of the broad-horned flour beetle (Gnatocerus cornutus) was reported to be (lJR,4i, 5S)-(+)-acoradiene (33) by Tebayashi et al. [72]. Scheme 47 shows Mori s synthesis of (lRy4Ry5S)-33 [73]. The key-step was the ring-closing olefin metathesis of A to give B. An X-ray analysis of C confirmed the structure shown. The product (lJR,4JR,5S)-33, however, was different... 

There are other examples of volatile hydrocarbon pheromones in beetles that have been researched less extensively. One of these is from the broad-homed flour beetle, Gnatocerus cornutus (F.) (Coleoptera Tenebrionidae), a common stored-product pest. Tebayashi et al. (1998) found that males produce at least one compound that was attractive to both sexes in laboratory bioassays and at sub-nanogram levels. The compound was identified as the sesquiterpene (+)-acoradiene. The beetle-derived enantiomer was subsequently synthesized... 

Acoradiene and its isomers are widespread, the isomer shown is isolated from vetiver oil but one of its double-bond isomers is reported to be the aggregation pheromone of the Broad-homed flour beetle (Gnatocerus cornutus). A pathway to acoradiene is shown in Scheme 11.61. 

Tashiro T, Kurosawa S, Mori K. Revision of the stmcture of the major aggregation pheromone of the broad-homed flour beetle Gnatocerus cornutus) to (15, 4R,5R)-alpha-acora-diene by its synthesis. Biosci. Biotechnol. Biochem. 2004 68 663-670. 

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