https://doi.org/10.1351/goldbook.P04614
A @PT07460@ of aryl or acyl @E02219@ to give the [1,3]-rearranged product (as well as the [1,5]-rearranged product):
P04614.png
Source:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2261 [Terms] [Paper]