The photoreaction behaviors of 2,3-bis[2-(4-chlorophenyl)ethenyl]pyrazine (1) in the crystalline state as well as in acetonitrile solution were examined mechanistically. In the crystalline state, stepwise [2+2] cycloadditions occurred between two facing molecules under the crystal lattice control to give a [2.2]orthocyclophane derivative in 74% yield. Photoirradiations of 1 in acetonitrile solution were also performed. In this case, products distributions were changed depending on the cut off wavelength.