Mechanistic Investigation of the Acenaphthenequinone Sensitized Bartlett Photoepoxidation of Olefins. Concomitant Oxidation of the Sensitizer.

摘要

Photolysis of acenaphthenequinone in Ch2Cl2 solution continuously saturated with oxygen generates 1,8-naphthalic anhydride in 80% isolated yield. When an olefin is included in the reaction solution it is converted to a mixture of oxidized products consisting mainly of allylic hydroperoxide and epoxide. It is demonstrated that the quantum efficiency for quinone oxidation is independent of quinone and olefin concentration. A mechanism is suggested for which an initial reaction between excited quinone and oxygen results in covalent bond formation. Subsequent rearrangement of this intermediate accounts for the results observed. (Author)