One-pot regioselective synthesis of dihydronaphthofurans and dibenzofurans

A regioselective approach for the synthesis of substituted naphthofurans and dibenzofurans has been demonstrated through a ring transformation reaction of suitably functionalized 2H-pyran-2-ones by reaction with 6,7-dihydro-5H-benzofuran-4-one and 7-methoxybenzofuran-3-one, respectively, in high yields. The novelty of the procedure lies in the creation of an aromatic ring transformed by 2H-pyran-2-one involving the –COCH2– moiety of a cyclic ketone.