Photochemische Reaktionen. 121. Mitteilung. Zur Photochemie von ε,ζ-Methano-α,γ-dienonen und 7,8-Methano-1,3,5-trienen
✍ Scribed by Keitaro Ishii; Bruno Frei; Hans Richard Wolf; Oskar Jeger
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- German
- Weight
- 787 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0018-019X
No coin nor oath required. For personal study only.
✦ Synopsis
Photochemistry of ε,ζ‐Methano‐α,γ‐dienones and 7,8‐Methano‐1,3,5‐trienes
Irradiation of the δ‐cyclopropyl‐dienone (E)‐6 (λ ≥ 347 nm) gives (Z)‐6, 10 (1,5‐sigmatropic H‐shift), (E/Z)‐9 (electrocyclic process involving C(ε), C(ζ)‐cleavage) and 11 (ring opening).
The corresponding 6‐cyclopropyl‐triene (E)‐7 gives on singlet excitation (δ > 280 nm) 14 (1,5‐sigmatropic H‐shift) and, to a smaller extent, the bicyclo [3.2.0] heptenyl‐dienes (E/Z)‐13. However, on triplet excitation (λ ≥ 347 nm, benzophenone) (E)‐7 gives (E/Z)‐13 as the main products. On both ^1^π,π*‐ and ^3^π,π*‐excitation, (Z)‐7 and 15 are formed in small amounts.