https://doi.org/10.1351/goldbook.PT07455
Photoinduced reaction of conjugated compounds (e.g., enones and carboxylic acid derivatives) leading to loss of conjugation. 

Note: This reaction has important synthetic applications for the synthesis of frameworks of numerous natural products, such as β,γ-unsaturated carboxylic acids from photoexcitation of α,β-unsaturated carboxylic acid derivatives, excluding the use of strong bases, as required for similar isomerizations performed in the ground state.