Peter J. Wagner, Richard G. Zepp, Kou-Chang Liu, Michael Thomas, Ta-Jyh Lee, Nicholas J. Turro,
Competing photocyclization and photoenolization of phenyl .alpha.-diketones Journal of the American Chemical Society. ,vol. 98, pp. 8125- 8134 ,(1976) ,
10.1021/JA00441A042