aromatic photocycloaddition

https://doi.org/10.1351/goldbook.AT07327
Inter- and @[email protected] photochemical processes involving the addition of a C–C double (or triple) bond (i) to the 1,2-positions of an arene in which case it is called an ortho @[email protected], with formation of a benzocyclobutene (or a benzocyclobutadiene) derivative, (ii) to the 1,3-positions of an arene in which case it is called a meta @[email protected], with formation of tricyclo[3.3.0.02,8]oct-3-ene (or octa-3,6-diene) derivatives, or (iii) to the 1,4-positions of an arene in which case it is called a para @[email protected], with formation of bicyclo[2,2,2]oct-2-ene (or octa-2,5-diene) derivatives.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 303 [Terms] [Paper]