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Photochemische Reaktionen 119. Mitteilung [1] Zur Photospaltung konjugierter γ,δ-Epoxyenone. UV.-Bestrahlung von 3-(1′,2′-Epoxy-2′-methyl-prop-1′-yl)-5,5-dimethyl-2-cyclohexen-1-on

✍ Scribed by Guy De Weck; Hans Richard Wolf

Publisher: John Wiley and Sons
Year: 1981
Tongue: German
Weight: 718 KB
Volume: 64
Category: Article
ISSN: 0018-019X
DOI: 10.1002/hlca.19810640124

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✦ Synopsis

Photocleavage of Conjugated π,π‐Epoxyenones. UV.‐Irradiation of 3‐(1′,2′‐Epoxy‐2′‐methyl‐prop‐1′‐yl)‐5,5‐dimethyl‐2‐cyclohexene‐1‐one

On ^1^π,π*‐excitation (δ = 254 nm) 9 undergoes cleavage of the C(δ), C(δ)‐bond yielding 17 and a, which gives 18 by photofragmentation. In presence of maleinic ester the photolysis of 9 yields 20, in presence of methanol 21 and 22 are obtained. By photocleavage of the C(δ), O‐bond 9 is converted into b giving 14. Photolysis of 14 yields 15 (A + B) and 16.

On ^1^n,π*‐excitation (δ λ⩾ 347 nm) of 9 cleavage of the C(δ), O‐bond (9 → b) seems to be the preferred reaction, whereas products of a are formed in traces, only.

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