Total Synthesis of Bulgarein

Abstract

Here we report an efficient and short total synthesis of bulgarein (1), a natural compound from Bulgaria inquinans with cytotoxic activity. Key steps in the total synthesis are a Suzuki-Miyaura coupling reaction of two substituted naphthalene derivates followed by a polyphosphoric acid (PPA) mediated condensation reaction to form the benzo[j]fluoranthene skeleton. Bulgarein (1) was achieved over 4 steps with an overall yield of 25 %.