H2SO4-Mediated Stereocontrolled Annulation of Oxygenated Naphthalenes and 4-Alkenols: One-Pot Synthesis of Tetanthrenes.

H2SO4-mediated one-pot stereocontrolled (4 + 2) annulation of 4-alkenols and oxygenated naphthalenes provided tetanthrenes in CH2Cl2 at 25 °C for 10 h. The use of various Brønsted acids or Lewis acids was investigated for a facile and efficient transformation. A plausible mechanism has been proposed.