products were separated by vpc. l-Phenyl-3,3-dimethylbutane: nmr (CDC13) 6 0.94 (s, 9, t-Bu), 1.50 (m, 2, RCHZR), 2.55 (m, 2, ArCHZR), and 7.20 (9, 5, phenyl); ir (film) 1370,1390 (unsym doublet, t-Bu), and 698, 733 em-' (C~HB); mass spectrum (75 eV) m/e (relative intensity) 162 (14) (Cl~H18+), 57 (100) ((AH9+). l-Phenyl-3,3-dimethylbutene: nmr (CDCls) 6 0.94 (8, 9, t-Bu), 6.24 (s, 2, vinyl), and 7.25 (m, 5, phenyl); ir (film) 1375, 1390 (unsym doublet, t-Bu), 975 (trans -CH=CH-), and 747, 694 em-' (-C6Hi); mass spectrum (75 eV) m/e (relative intensity) 160 (27) (CI%H~~+), 145 (100) (M+ -15), 91 (50) (C7H7+), and 57 (7) (C4Ho+).A repetition, using the products above in place of the p-bromostyrene, gave no change in the composition of the product, indicating that the olefin is not reduced by the organometallic.Reaction of Lithium Diphenylcopper with trans-and cis+ Bromostyrenes.-To a suspension of 5.2 g (0.027 mol) of cuprous iodide in 10 ml of ether at 0" was added 25 ml (0.055 mol) of commercial phenyllithium in 70: 30 benzene-ether:The solution was cooled to -78", and a solution of 1.0 g (0.0055 mol) of vpc-purified trans-@-bromostyrene in 10 ml of ether was added. The solution was stirred at -78" for 3 hr and then worked up in the usual way to give 1 .O g of a heavy oil containing large amounts of biphenyl and styrene (8070 of the mixture). The stilbene fraction (20y0) contained, by vpc analysis and isolation, using a 20y0 Apiezon L column, 1670 cis-stilbene, mp 4-7" (lit.* mp 5-6'), and 84% trans-stilbene, mp 124-125 (lit.9 mp 124").When the above reaction was repeated using vpc-purified cis-pbromostyrene, the stilbene fraction contained 7oY0 cis-and 30% trans-stilbene.
RegistryNo.-LiCuR2, R = i-C3H7, 24012-11-1; LiCuRz, R = t-CdH9, 23924-63-2; LiCuR2, R = Ph,