photocycloaddition

https://doi.org/10.1351/goldbook.PT07451
@I03098@ photochemical process leading to carbo- or hetero- cyclic ring systems by formation of two new single bonds, either by a @C01234@ (e.g., a concerted addition) or by multi-step processes (e.g., the Paternò–Büchi reaction).
Note:
@T06503@ photocycloadditions are two-step processes involving the formation of diradical intermediates.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 388 [Terms] [Paper]