Biprorulus bibax Bugs

Hemiacetal 25 [(3 ,4S,l E)-3,4-bis(r-butenyl)tetrahydro-2-furanol] is the male pheromone of the spined citrus bug (Biprorulus bibax). Scheme 38 summarizes Mori s synthesis of 25 [61]. Claisen rearrangement (A B) and lipase-catalyzed asymmetric acetylation [meso-C >(5S,6R)-D] were the two key steps of the synthesis. Further purification of D was executed at the stage of its crystalline derivative E. In this particular case, the unnatural (3S,4R,l E)-25 was as active as the natural (3R,4S,VE)-25. Accordingly, a more efficient synthesis of ( )-25 was achieved by the rearrangement of F, avoiding the use of toxic HMPA [62]. 

The spined citrus bug (Biprorulus bibax) is a pest of citrus in southern Australia. The major component (74, Figure 4.5) of the male-produced pheromone of B. bibax was isolated and identified by the joint work of James in Australia and Oliver et al. in the USA. Oliver found by chiral GC analysis that the insect produces a single enantiomer of 74. In 1992 I became interested in clarifying the absolute configuration of this pheromone, because Dr. Oliver requested me to do so. 

Suzuki T, Morita K, Ikemiyagi H, Watanabe K, Hiroi K, Katoh T (2006) Synthesis of the hemiacetal pheromone of the spined citrus bug biprorulus bibax utilizing an iridium catalyzed oxidative lactonization. Heterocycles 69 457-461... 

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