Polycyclic compounds by sunlight exposure of the drug rosuvastatin in water

Irradiation of rosuvastatin in water by sunlight or UV lamp (Pyrex) affords cyclic compounds. The main photo-induced reaction is cyclization of the drug to give diastereomeric dihydrobenzoquinazolines. Products derived from side-chain loss were also isolated in the irradiation mixture, and characterized as dihydrobenzoquinazoline and benzoquinazoline derivatives by spectroscopic means. Photoproducts structure elucidation and mechanistic hypothesis are reported.