Yang photocyclization

https://doi.org/10.1351/goldbook.YT07500
@I03130-1@ @C01025@ of @D01765@ of different sizes (1,4-, 1,5-, 1,6-, 1,7-, 1,8-@D01765@, as well as very remote @D01765@) formed through @I03130-2@ hydrogen @A00045@ by an excited ketone, yielding cyclic @A00204@ of different sizes.
Source:
PAC, 2007, 79, 293. (Glossary of terms used in photochemistry, 3rd edition (IUPAC Recommendations 2006)) on page 441 [Terms] [Paper]