The photochemistry of eno-and endo-7-methylbicyclo [4.1. 0] hept-2-ene (7-methyl-2- norcarene) upon direct and toluene-sensitized photolysis has been investigated. Direct photolysis of the two isomers in hydrocarbon solution with monochromatic 214-nm light leads to widely divergent photobehavior. Ring opening, yielding cis-5-methyl-1, 3, 6- heptatriene (via a formal [27r+ 2w+ 2u] process), and exo-endo isomerization are major ...
