作者:Masanori Utaka、Manabu Nakatani、Akira Takeda
DOI:10.1016/s0040-4020(01)96588-3
日期:1985.1
The dye-sensitized photo-oxygenation of the enols of 1,2-cyclohexanedione (1) has been carried out in various solvents at -70°-40°. Singlet oxygen is involved in the reaction as evidenced by quenching and rate enhancement observed in deuterated methanol. The reaction proceeds by an ene reaction with singlet oxygen to afford the hydroperoxide, 4, which closes to a five-membered endoperoxide, 5, as a
1,2-环己二酮(1)的烯醇的染料敏化光氧合反应已在各种溶剂中于-70°-40°进行。单重态氧参与反应,这是通过在氘化甲醇中观察到的淬灭和速率提高所证明的。该反应通过与单线态氧的烯反应进行,得到氢过氧化物4,氢过氧化物4作为主要途径接近于五元内过氧化物5,而作为次要途径接近于二氧杂环丁烷6。内过氧化物5会分解为5-氧代链烷酸(2),并释放出一氧化碳,或被溶剂(MeOH或EtOH)捕集,得到5-羧基-2-羟基戊酸甲酯或乙基乙酯(3)。3-甲基-1,2-环己二酮(1a)的烯醇与2,3-二甲基-2-丁烯(TME)的竞争表明,烯醇与TME一样对单线态氧具有反应性。