A detailed examination of the published methods for the reduction of biphenyl, via the alkali metal adducts, has shown that the phenylcyclohexadienes 3 and 4 may be formed depending on the conditions employed. The more reduced compounds, phenylcyclohexene and phenylcyclohexane, may also be produced. Dienes 1 and 2 can be prepared by the elimination of certain groups from the substituted 1-phenylcyclohexenes (6). Dienes 1-4 ...
[Singleton, Daniel A.; Schulmeier, Brian E.; Hang, Chao; Thomas, Allen A.; Leung, Shun-Wang; Merrigan, Steven R. Tetrahedron, 2001 , vol. 57, # 24 p. 5149 - 5160]
