AbstractThe photolysis of 7,8‐dihydro‐4‐hydroxy‐β‐ionone (6) was investigated together with its acetate and isopropyl ether 7 and 8, respectively. Irradiation (λ > 245 nm) of 6 in MeCN or i‐PrOH at temperatures between 25° and −65° leads to the tricyclic ethers 9, 10 and 13A + B, and to the spirocyclic ethers 11 and 12, which are all known types of photoproducts, previously obtained on photolysis of 7,8‐dihydro‐β‐ionone (1). The same types of products are obtained on irradiation of the acetate 7 and the isopropyl ether 8. On the other hand, irradiation of the hydroxy compound 6 in MeCN or i‐PrOH at temperatures between −35° and −65° leads to the new tricyclic tertiary alcohols 14 and 15 as the major products. Their formation involves an intramolecular trapping of a carbocation by the neighbouring OH group, thus, supporting the previously proposed mechanism of the transformation 1 → 5. For structure proof, the tricyclic alcohol 14 and the pheny1 carbamate 42, derived from 9, were subjected to X‐ray analysis.