Reactivity of naphthol towards nucleophiles in anodic oxidation

Reactivity of the anodic oxidation of 4-methoxy-1-naphthol in the presence of nucleophiles has been investigated. The reaction with electron-rich alkenic nucleophiles such as 1-methoxy-4-propenylbenzene and isosafrole gave a very high yield, whereas the reaction with dihydropyran and dihydrofuran gave a moderate yield, but with ethyl vinyl ether gave a very low yield of the substituted dihydronaphthofuran derivatives and , respectively. Unexpectedly, the glycosyl derivative was preferentially produced rather than naphthofuran upon using as a nucleophile. In addition, the dimers and were obtained in moderate yield without addition of nucleophile to . The mechanism of the oxidation reactions including the [3+2] and [5+2] cycloaddition were discussed.