A Short Synthesis of the Long-Tailed Mealybug Pheromone in both Racemic and Enantiopure Forms

The sex pheromone of the long-tailed mealybug has been synthesized in both racemic and enantiopure forms from simple racemic acyloin acetate and chiral acyloins (both <i>R</i> and <i>S</i>). An efficient iron-mediated intramolecular radical cyclization has been used to achievethe efficient formation of a cyclopentane core and bicyclic lactone bearing two quaternary centers under mild conditions. The resulting cyclopentane core and bicyclic lactones were elaborated to give the target pheromone.