𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Photochemische Reaktionen. 88. Mitteilung [1]. Zur Photochemie des Iso-methyl-β,(E)-jonon-epoxids

✍ Scribed by Beat Rudolf Von Wartburg; Hans Richard Wolf; Oskar Jeger

Publisher
John Wiley and Sons
Year
1976
Tongue
German
Weight
690 KB
Volume
59
Category
Article
ISSN
0018-019X

No coin nor oath required. For personal study only.

✦ Synopsis

Photolysis of iso‐methyl‐β,(E)‐ionone‐epoxide

On n, π*‐excitation (λ ≥ 347 nm) the title compound 7 isomerizes to the (Z)‐enone‐epoxide 8, which yields the bicyclic alkohol 9 in a second photochemical step. The photoisomerization 8 → 9 is a further example for the influence of a methyl substituent at C(α) of an enone‐chromophore on the nature of the photochemical processes.

On UV. irradiation in the presence of traces of hydrochloric acid 7 gives quantitatively the furane 10.

📜 SIMILAR VOLUMES

Photochemische Reaktionen. 89. Mitteilun
Photochemische Reaktionen. 89. Mitteilung [1]. Zur Photochemie konjugierter Epoxy-diene I. Versuche mit (E),β-Jonyliden-epoxiden
✍ Alex Peter Alder; Hans Richard Wolf; Oskar Jeger 📂 Article 📅 1976 🏛 John Wiley and Sons 🌐 German ⚖ 469 KB

**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, under

Photochemische Reaktionen. 97 Mitteilung
Photochemische Reaktionen. 97 Mitteilung [1]. Zur Photochemie konjugierter Epoxy-diene II. Versuche mit (E)-β-Jonyliden-epoxiden
✍ Alex Peter Alder; Hans Richard Wolf; Oskar Jeger 📂 Article 📅 1978 🏛 John Wiley and Sons 🌐 German ⚖ 923 KB

**Photolysis of Conjugated Epoxy‐dienes** Direct and sensitized excitation of the (__E__)‐β‐ionylidene‐epoxides **1** and **4** leads to different types of isomerizations. Thus photocycloelimination to the cyclopropene‐ketones **2** and **6** is only achieved by ^1^(π, π\*)‐excitation (λ=254 nm), w

Photochemische Reaktionen 122. Mitteilun
Photochemische Reaktionen 122. Mitteilung [1]. Zur vinylogen β-spaltung von epoxy-enonen: Photoisomerisierung des 3,4:5,6-diepoxy-5,6-dihydro-β-jonons
✍ Norbert Bischofberger; Guy De Weck; Bruno Frei; Hans Richard Wolf; Oskar Jeger 📂 Article 📅 1981 🏛 John Wiley and Sons 🌐 German ⚖ 716 KB

**Vinylogous β‐Cleavage of Epoxy‐enones: Photoisomerization of 3,4: 5,6‐Diepoxy‐5,6‐dihydro‐β‐ionone** On ^1^n,π\*‐excitation (λ>347 nm), 3,4:5,6‐diepoxy‐5,6‐dihydro‐β‐ionone (__(E)__‐**3**) shows the typical behaviour of α,β‐unsaturated γ,δ‐epoxy ketones furnishing the __(Z)__‐enone **3** and by C

Photochemische Reaktionen. 105. Mitteilu
Photochemische Reaktionen. 105. Mitteilung [1]. Zur Photochemie optisch aktiver λ, δ-Epoxy-enone: Racemisierung und Cyclisierung von (−)-4-Methyliden-5,6-epoxy-5,6-dihydro-β-jonon und (−)-4-Oxo-5,6-epoxy-5,6-dihydro-β-jonon
✍ Bruno Frei; Hans Richard Wolf; Oskar Jeger 📂 Article 📅 1979 🏛 John Wiley and Sons 🌐 German ⚖ 542 KB

**The photochemistry of optical active λ, δ‐epoxy‐enones. Racemization and cyclization of (−)‐4‐methylidene‐5,6‐epoxy‐5,6‐dihydro‐β‐ionone and of (−)‐4‐oxo‐5,6‐epoxy‐5,6‐dihydro‐β‐ionone** UV.‐irradiation (λ ≥ 347 nm as well as λ = 254 nm) converts the conjugated λ, δ‐epoxy‐enones (−)‐**2** and (−)