Synthesis of various angular methylfurocoumarins

A number of new methylfurocoumarins, in wich the furan, benzene and pyrone rings are annulate angularly with various arrangements, were synthesized. The synthesis were performed starting from the appropriate hydroxycoumarins on which the furan ring was built. According to this scheme, methyl groups could be introduced into positions which look most promising for enhancement of photoreactivity in the respect to the corresponding unmethylated compounds