A one-pot stereospecific synthesis of 1, 5-dien-3-ynes (Z) or (E) is described, based upon a palladium-catalyzed cross-coupling reaction between butenynylzinc bromide, generated in situ from 1, 1-difluoroethylene, and an adequate iodoalkene. These dienynes are converted into the corresponding trienic compounds by (Z) semi-hydrogenation.
