Photosensitized oxidation of suberosin yielded suberenol (2), isosuberenol (6) and, under certain conditions, 6,6'-ethylenebis(7- methoxy-2H-1-benzopyran-2-one). The epoxy alcohol (7a), its methyl ether and the aldehyde (3) were also obtained, but these are believed to be artefacts formed under the conditions of workup. Autoxidation of suberosin does not appear to occur readily. Other oxygenated derivatives of suberosin were prepared by chemical methods. ��� Dehydration of suberenol and isosuberenol yielded the diene (5) which on treatment with acid gave in low yield a bis-coumarin, isomeric with cyclobisuberodiene, for which structure (24) is suggested.