Photosynthesis of furocoumarin- and furochromone-types potential intercalative alkylating and oxidizing agents of dna through photooxidations using γ-ray

The photooxygenation of imperatorin (1a) under γ-ray irradiation afforded the hydroperoxides 2a and 3a. Similarly, the photooxygenation of alloimperatorin (1b) gave the hydroperoxide (2b). Visnagin (1c) was also photooxygenated to give the hydroperoxide (2c) as sole product. On the other hand, the photooxygenation of khellin (1d) gave the endoperoxide (2d) as a sole product. The epoxidation of imperatorin (1a) using hydrogen peroxide under γ-ray irradiation afforded the epoxide 5a. Similarly visnagin (1c) and khellin (1d) were epoxidized to give the epoxides 5c and 5d.