Syntheses and Characterizations of the Dye Sensitized Photooxygenation Products and the Heterocycles of Naphthofuran Derivatives

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 ac tion of 1 with BBr₃. 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, ¹³C -NMR,IR,MS,UV,FL and elemental analysis, their synthetic mechanism were also suggested.