Enantioselective synthesis of Anomala osakana pheromone and Janus integer pheromone: a flexible approach to chiral gamma-butyrolactones.

The enantioselective synthesis of Anomala osakana pheromone and Janus integer pheromone has been achieved without using any protecting groups. The synthesis involved using an asymmetric alkynylation to obtain gamma-hydroxy-alpha,beta-acetylenic esters with high ee (84%) and yields ( approximately 80%), followed by selective hydrogenation and lactonization in high overall yields (87% and 89%).