Abstract: Irradiation of cis-a-phenylcinnarnic acid in the presence of tetramethylethylene in degassed ether gives trans-l, 2-diphenyl-3, 3, 4, 4-tetrarnethylcyclobutane. The mechanistic path of the reaction is shown to involve initial isomerization of cis-a-phenylcinnarnic acid to the trans-and cis-p-lactones. The cis-@-lactone is isolated in 79 yield. Irradiation of the cis- @-lactone in the presence of tetramethylethylene gives trans-l, 2-diphenyl-3, 3, 4, 4- ...
[Ishii, Akihiko; Ding, Meng-Xin; Maeda, Kiyoto; Nakayama, Juzo; Hoshino, Masamatsu Bulletin of the Chemical Society of Japan, 1992 , vol. 65, # 12 p. 3343 - 3349]
