Ylids generated from diphenyl allylic phosphonium salts reacted with aliphatic aldehydes containing a terminal oxygen functionized group in the absence of lithium salt to give E, E-conjugated dicncs. The stereoselectivity depends mainly on the base used, the allylic part of phosphonium salts also shows some effect on stereochemistry. Eight conjugated dienic insect sex pheromones and related analogues with different E-selectivities were obtained...
