Sensitized Photooxygenation of 6-Heteroatom-Substituted Fulvenes: Primary Products and Their Chemical Transformations

Article abstract of DOI:10.1021/jo00110a043

Sensitized photooxygenation of 6,6-diethoxyfulvene (1) and 6,6-(ethylenedithio)fulvene (9) at -78 deg C afforded diethoxyfulvene endoperoxide 2 and (ethylenedithio)fulvene endoperoxide 10, respectively, as primary products.Further irradiation resulted in formation of the novel bisperoxides 3 and 11 from <2 + 2> cycloaddition of ¹O2 to the exocyclic double bond of the corresponding endoperoxides.The initial endoperoxides were characterized by NMR at low temperature and underwent a variety of chemical transformations to give highly oxygenated cyclopentane derivatives.In contrast, photooxygenation of 6,6-dipiperidinofulvene (16) and 6-(dimethylamino)fulvene (17) did not lead to chemical reaction; these compounds physically quench ¹O2 with rate constants on the order of 1E8 M^-1 s^-1.