作者:Kazuhiro Maruyama、Keiichi Ono、Jiro Osugi
DOI:10.1246/bcsj.45.847
日期:1972.3
The relative photochemical reactivity of α-diketones, in particular, 9,10-phenanthraquinone, 1,2-naphthoquinone, acenaphthoquinone, benzil, 4,4′-dimethylbenzil, 2,4,6-trimethylbenzil, 2,5,2′,5′-tetramethylbenzil, 2,3,5,6-tetramethylbenzil, 2,4,6,2′,4′,6′-hexamethylbenzil, phenylglyoxal, 2,5-dimethylphenylglyoxal, and 2,4,6-trimethylphenylglyoxal was investigated in hydrogen donating solvents. Type of the product and relative reactivity differ widely according to the structure of α-dike tones. Whereas 9,10-phenanthraquinone gives 1,4-adduct (V) in a hydrogen donating solvent (THF), 2,5,2′,5′-tetramethylbenzil gives 2-hydroxy-2-(2′,5′-dimethylphenyl)indanone (VII) via intramolecular hydrogen abstraction in nearly quantitative yield. No photochemical reaction of 2,4,6-trimethylbenzil or 2,3,5,6-tetramethylbenzil could be observed in the same solvent even under a long irradiation.
α-二酮,特别是9,10-菲醌、1,2-萘醌、苊醌、苯偶酰、4,4′-二甲基苯偶酰、2,4,6-三甲基苯偶酰、2,5,2′,5′-四甲基苯偶酰、2,3,5,6-四甲基苯偶酰、2,4,6,2′,4′,6′-六甲基苯偶酰、苯乙二醛、2,5-二甲基苯乙二醛和2,4,6-三甲基苯乙二醛在供氢溶剂中的光化学反应活性被研究。产物的类型和相对反应活性根据α-二酮的结构差异很大。9,10-菲醌在供氢溶剂(四氢呋喃)中生成1,4-加合物(V),而2,5,2′,5′-四甲基苯偶酰通过分子内氢抽提以接近定量的产率生成2-羟基-2-(2′,5′-二甲基苯基)茚满酮(VII)。在相同溶剂中长时间照射下,2,4,6-三甲基苯偶酰或2,3,5,6-四甲基苯偶酰的光化学反应无法被观察到。