Stereoselective synthesis of the obscure mealybug pheromone by hydrogenation of a tetrasubstituted alkene precursor

An improved diastereoselective synthesis of (1R∗,2R∗,3S∗)-1-acetoxymethyl-2,3,4,4-tetramethylcyclopentane 1, the sex pheromone of the obscure mealybug, Pseudococcus viburni, is described. The key step was diastereoselective catalytic hydrogenation of the tetrasubstituted double bond in 2,3,4,4-tetramethyl-cyclopent-2-enone 4 to give the thermodynamically less favored cis-2,3,4,4-tetramethyl-cyclopentanone 3a.