“…Bergelson, et al (22,25) have reported on the effect of solvent and of additives on the cis/trans ratio of isomers. They studied, in particular, the formation of 1-phenyl-l-butene from benzylidenetriphenylphosphoranc and propionaldehyde and from propylidenetriphenylphosphorane and bcnzaldcliydo.…”