Insect Pheromones Made Catalytically

From the promising new family of Z-selective olefin metathesis catalysts comes a synthetic strategy for preparing insect pheromones (Angew. Chem. Int. Ed., DOI: 10.1002/anie.201206079). Although highly useful for environmentally friendly insect control, cis-olefin-containing insect pheromones are difficult to synthesize, and their production generates large amounts of waste. Last year, Caltech’s Robert H. Grubbs and colleagues used one of the ruthenium-based Z-selective catalysts pioneered by Grubbs’s group to synthesize a monounsaturated cis-olefin-containing pheromone. Now, Grubbs’s group has expanded the catalyst’s repertoire to include short, simple syntheses of nine lepidopteran pheromones that EPA has approved for use as insecticide alternatives. Starting with oleyl alcohol and 11-eicosenol derived from vegetable oils, the group prepared the pheromones in good yields at mild temperatures, with better than 80% Z-selectivity in most cases. The researchers envision this strategy could be generalized to many analogous pheromones and be practical on an industrial scale.