In the presence of tetraphenylporphine and oxygen under irradiation of light at low temperature, naphthofurans 1 and 7 formed the corresponding dioxetanes 2 and 8, and followed by decomposition at room temperature to acetylacetoxyl naphthalene 4 and 9, respectively. 2 reacted with hydrogenchloride to give naphthofuran 6, in which two hydrogens at 3-methyl group and 9-position near the furan ring were substituted by chlorine group. 4 reacted with hydrogen chloride form hydroxy naphthofuran 3 by losing an acetyl group at its α-position, the same product was obtained by the action of 1 with BBr~3. In the presence of sodium acetate/acetic anhydride 4 cyclized to give 3-acetyl naphthopyrone 5. The structures of the above compounds were confirmed by using ^1H, ^1^3C-NMR, IR, MS, UV, FL and elemental analysis, their synthetic mechanism were also suggested.

Key words: PHOTOOXIDATION, SENSITIZATION, NAPHTHALENE P, HETEROCYCLIC COMPOUNDS, DYES, PYRANONE P, FURAN P, CYCLOADDITION REACTION, ORGANIC SYNTHESIS, FURAN P