Photochemische Reaktionen. 89. Mitteilung [1]. Zur Photochemie konjugierter Epoxy‐diene I. Versuche mit (E),β‐Jonyliden‐epoxiden

Photolysis of conjugated epoxy‐dienes UV.‐irradiation (λ = 254 nm) of ( E ),β‐ionylidene‐epoxide ( 3 ) in n ‐pentane gives the isomeric cyclopropene‐ketone 7 (90%) in a hitherto unreported type of photoreaction. The methylsubstituted ( E ),β‐ionylidene‐epoxide 6 , however, undergoes ( E/Z )‐photoisomerization to the ( Z ),β‐ionylidene‐epoxide 8 (91%).