AN ALKOXY RADICAL REARRANGEMENT OF PHOTOCYCLOADDUCT OF 4-HYDROXYCOUMARIN AND DIMETHYLBUT-2-ENE TO FUROCOUMARIN AND FUROBENZO-γ-pyrone. Coumarin–BENZO-γ-PYRONE TRANSFORMATION
The alkoxy radical generated from a fused cyclobutanol obtained by the photocycloaddition of 4-hydroxycoumarin and dimethylbut-2-ene rearranges to a furocoumarin and a furo-benzo-γ-pyrone. The results afford further insight regarding the mechanism of the formation of the furocoumarins.