Photoenolization of 2-(2-Methyl Benzoyl) Benzoic Acid, Methyl Ester: Effect of E Photoenol Lifetime on the Photochemistry
作者:Armands Konosonoks、P. John Wright、Meng-Lin Tsao、Jana Pika、Kevin Novak、Sarah M. Mandel、Jeanette A. Krause Bauer、Cornelia Bohne、Anna D. Gudmundsdóttir
DOI:10.1021/jo048055x
日期:2005.4.1
to formation of 5 via intermolecular H-atom abstraction followed by lactonization. Irradiation of 4 in 2-propanol gave compounds 6 and 7 that also come from intermolecular H-atom abstraction. In contrast, photolysis of an oxygen-saturated solution of 3 in 2-propanol yields products 8, 9, and 10, which were all formed from intramolecular H-atom abstraction and trapping of the corresponding biradical
3在氩气饱和的2-丙醇中的光解作用通过分子间H原子的提取继之以内酯化作用导致5的形成。在2-丙醇中辐照4得到化合物6和7,它们也来自分子间的H原子抽象。相反,氧饱和的溶液的光解3在2-丙醇收率的产品8,9,和10,将其从所有的分子内H-原子夺取形成并与氧的相应的双自由基俘获。甲醇中的3的激光快速光解表明形成了双自由基3BR(λmax330 nm,并且τ= 50 ns)通过分子内H原子抽象作为3的主要光反应性。双自由基3BR衰减为光烯醇3Z和3E(分别为λmax 390 nm,τ= 6.5μs和τ= 162μs )。相比之下,激光闪光光解4生成光烯醇4Z和4E(分别为λmax 390 nm,τ= 15μs和τ= 3.6 ms)。因此,光烯醇3E的寿命异常短,因此不会像我们对类似的光烯醇1E所观察到的那样,它不会进行分子内内酯化。光烯醇3Z衰减回3通过分子内1,5--H移位,而photoenol