Photochemical reactions. 133rd Communication. Photochemistry of epoxydienes of the ionone series: Influence of a methyl group at the diene side chain on the oxirane cleavage
作者:Alfons Pascual、Takehiko Nishio、Bruno Frei、Oskar Jeger
DOI:10.1002/hlca.19840670116
日期:1984.2.1
exclusively, leading to the conformers (Z)-2A and (Z)-2B. On singlet excitation (λ = 254 nm), apart from (Z)-2A + B, the cyclobutenes 3A + B are formed. However, the epoxydiene (E)-2 does not undergo reactions leading to carbene and C,O-bond cleavage products, which are normally observed on singlet and triplet excitation, respectively, of the epoxydienes of the ionone series.
在三重态激发下(λ> 280 nm,丙酮),环氧二烯(E)-2仅经历(E)/(Z)异构化,生成构象体(Z)-2A和(Z)-2B。在单重态激发(λ= 254 nm)上,除(Z)-2A + B外,还形成了环丁烯3A + B。但是,环氧二烯(E)-2不会发生导致卡宾和C,O键裂解产物的反应,这通常分别在紫罗兰酮系列环氧二烯的单线态和三线态激发下观察到。