There are various tips on how to assemble benzofuran rings. The commonest procedures are dehydration of phenoxyalkanone below acidic problem,104 dehydration of o-hydroxybenzophenone below acidic situation,105 decarboxylation of o-acetylphenoxyacetic acid or ester under alkaline affliction,106 and cyclization of o-hydroxybenzophenone to build benzof