Unexpected transformation of quinones to spirolactones and to naturally occurring naphthalenic compounds

In the last few years, natural quinones of the lapachol group have been used as starting points for the preparation of several bioactive heterocyclic compounds. Herein, we announce that lapachones, derivatives of lapachol, under certain conditions in the presence of inorganic reagents give unexpected products, spirolactones and naphthalenic derivatives, nordihydrolapachenone and tetrahydrotectol, both naturally occurring compounds. Nordihydrolapachenone was identified by X-ray analysis. Lapachol itself can also be converted to tetrahydrotectol.