Abstract 3-Phenylpropyllithium primarily formed by the addition of benzyllithium to ethylene in THF does not undergo an intramolecular 1, 3-proton shift to 1-phenylpropyllithium. Fast protonation by the solvent takes place instead, yielding n-propylbenzene and new ethylene. An equilibrium is then established between n-propylbenzene and additional benzyllithium, with the formation of toluene and 1-phenylpropyllithium; the equilibrium, however, strongly ...