gave tricyclic compounds (5H-pyrano[4,3,2-de][1,3]benzodioxin derivatives) and 3-alkylthio-2-alkenoyl-1,4-benzoquinones gave similar products (5H-pyrano[4,3,2-de][3,1]benzoxathiin derivatives). Each reaction initiates via γ-hydrogen abstraction by photoexcited quinone to produce diradical intermediates which intramolecularly cyclize to give the products.
3-烷氧基-2-烯酰基-1,4-苯醌在溶液中的辐照得到
三环化合物(5H-
吡喃[4,3,2-de][1,3]苯并二恶英衍
生物)和3-烷
硫基-2-烯酰基- 1,4-苯醌得到类似的产物(5H-
吡喃并[4,3,2-de][3,1]苯并沙
硫因衍
生物)。每个反应都通过光激发的醌提取 γ-氢来产生双自由基中间体,这些中间体在分子内环化得到产物。