The synthesis of enzopyrano[7,8-b][1,4]tetrahydrobenzodioxin-2-ones an
d 2H-benzopyrano[7,8-b][1,4]benzodioxin-2-ones is reported. This class
of compounds, prepared with the aim of obtaining new monofunctional p
hotosensitizing drug, appears to be ineffective upon UVA irradiation b
ut shows a moderate but significant activity in the dark.