Synthesis and photochemical reactivity towards the Paternó–Büchi reaction of benzo[b]furan derivatives: their use in the preparation of 3-benzofurylmethanol derivatives

4-Amino-2,7-dimethylbenzo[b]furan and 4-chlorobenzo[b]furan have been synthesized. The irradiation of 4-amino-2,7-dimethylbenzo[b]furan in the presence of benzaldehyde gave the corresponding endo adduct. The adduct can be hydrolysed to the corresponding 3-benzofurylmethanol derivative. The irradiation of the same compound in the presence of benzophenone gave the corresponding adduct. 4-Chlorobenzo[b]furan did not react with benzaldehyde while, in the presence of benzophenone, gave the corresponding adduct. The hydrolysis of this adduct gave the corresponding 3-benzofurylmethanol derivative.