Efficient Preparation of Terminal Conjugated Dienes by Coupling of Dienol Phosphates with Grignard Reagents under Iron Catalysis

An efficient new route to prepare stereoselectively terminal conjugated dienes by coupling Grignard reagents and dienol phosphates in the presence of Fe(acac)₃ is described. The synthetic utility of this new iron-catalyzed procedure is illustrated by the synthesis of the pheromone of Diparopsis castanea according to a very expeditious strategy.