Abstract: Lithium reacts with 5-chloro-4, 4-diphenyl-2-pentyne (7a) and with l-chloro-5, 5- dimethyl-2, 2-diphenyl-3-hexyne (7b) in THF at-75 OC to give 2, 2-diphenyl-3- pentynyllithium (14a) and 5, 5-dimethyl-2, 2-diphenyl-3-hexynyllithium (14b), respectively; when the THF solutions of these organolithium reagents are warmed to 0 OC,[1, 2] migration of the acetylenic group of each occurs to produce 1, I-diphenyl-3-pentynyllithium (16a) ...