6719-33-1Relevant academic research and scientific papers
DYE-SENSITIZED PHOTO-OXYGENATION OF 1,2-CYCLOHEXANEDIONES
Utaka, Masanori,Nakatani, Manabu,Takeda, Akira
, p. 2163 - 2168 (2007/10/02)
The dye-sensitized photo-oxygenation of the enols of 1,2-cyclohexanedione (1) has been carried out in various solvents at -70 - 40 deg C.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 major path or to dioxetane (6) as a minor one.The endoperoxide, 5, decomposed to 5-oxoalkanoic acid (2) with evolution of carbon monoxide or was trapped by the solvent (MeOH or EtOH) to give methyl or ethyl 5-carboxy-2-hydroxypentanoate (3).Competition between the enol of 3-methyl-1,2-cyclohexanedione (1a) and 2,3-dimethyl-2-butene (TME) has shown that the enol is as reactive as TME toward singlet oxygen.
PHOTOSENSITIZED OXYGENATION OF THE ENOL FORMS OF 1,2-CYCLOHEXANEDIONES
Utaka, Masanori,Nakatani, Manabu,Takeda, Akira
, p. 803 - 806 (2007/10/02)
The enols of 1,2-cyclohexanediones have been found to undergo a photosensitized oxygenation in methanol to afford 5-oxoalkanoic acids and methyl 5-carboxy-2-hydroxypentanoates with liberation of carbon monoxide with a remarkable temperature dependency of the product distribution, which is best accounted for in terms of trapping of a five-membered endoperoxide intermediate by methanol.
