The photochemistry of a diepoxy ketone

In dilute ethanol or tertiary butanol solutions irradiated with light of wavelength 300 nm, 1:1', 3:4-diepoxy-1-methyl-2- tetralone (I) was found to rearrange to the phenols (III) and (XIX) and to the pyrone (XXI). The identities of (XIX) and (XXI) were confirmed by synthesis whilst the identity of (III) was confirmed by comparing its properties with those of an authentic sample. Possible rearrangement mechanisms leading to the formation of these products are described.