Reaction of Allylbenzene with n-Butyllithium in Tetrahydrofuran

Abstract The reaction products between allylbenzene and n-butyllithium in tetrahydrofuran at 60°C were fractionated and investigated by elementary analysis, a molecular-weight determination, and a study of the IR, UV, and NMR spectra. The products were hydrocarbons and alcohols, the latter of which were formed by the reaction of the carbanions with tetrahydrofuran. The main products were 3-phenylheptene-2,5-methyl-6-phenyldecane, 5-phenyl-5-heptene-1-ol, 5-phenyl-5-vinylnonane-1-ol, and 5-phenyl-5-vinylnonane-1,9-diol. 3-Phenylheptene-1 was not obtained. In the resonance structures of allyl anions, a and b, Ph-\barCR–CH=CH2 (a) ↔ Ph–CR=CH–CH2− (b), the reaction with tetrahydrofuran took place only in the form a. The observed results are correlated with those of the anionic polymerization of trans-β-methylstyrene reported previously.