Investigating the photochemical properties of an arenyl dienol.

Upon irradiation with UV light, an arenyl dienol was transformed into linear and angular meta photocycloadducts and ortho derived photoadducts. Extended exposure to UV radiation resulted in the formation of other degradation products, which shed light on the chemical processes taking place. One of the linear meta photocycloadducts was thermally unstable and underwent further thermal and photochemical transformation, while the ortho-derived photocycloadducts ring-opened and eliminated methanol to afford a cyclooctadienone product.