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Photochemical reactions. 142nd communication. Photochemistry of a 6,7-epoxy-1,3-diene of the ionone series

✍ Scribed by Peter Mathies; Bruno Frei; Oskar Jeger

Publisher
John Wiley and Sons
Year
1985
Tongue
German
Weight
333 KB
Volume
68
Category
Article
ISSN
0018-019X

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✦ Synopsis

Abstract

On singlet excitation (Ξ» = 254 nm), the epoxydiene (E)‐3 underwent (E)/(Z)‐isomerization, electrocyclic ring closure of the diene side chain leading to the cyclobutenes 4A + B, and rearrangement to the cyclohexanones 5A + B. Compounds 5A + B were presumably formed in a series of processes including a 1,3‐acyl shift of the homoconjugated ketone 8, arising from (Z)‐3 by a 1,5‐H‐shift accompanied by cleavage of the C,O‐bond of the oxirane.

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