Asymmetric synthesis of the Japanese beetle pheromone via boronic esters

The pheromone of the Japanese beetle, [R-(Z)]-5-(1-decenyl)dihydro-2(3H)-furanone (7), has been synthesized efficiently in high enantiomeric purity via 1,2-dicyclohexyl-1,2-ethanediol boronic esters. The synthetic route involves reaction of an α-chloro boronic ester with an alkynyllithium, and provides the first successful example of this substitution process in an asymmetric synthesis.