Total synthesis of (±)-auranthine confirmed its refined structure

Abstract

Auranthine, isolated in 1986 from Penicillium aurantiogriseum, is a fungal benzodiazepine. Through the successful total synthesis of (±)-auranthine, we confirmed the refined structure of natural (−)-auranthine. We established that natural (−)-auranthine is a fused quinazolino benzodiazepine dione 1 featuring an acyclic aliphatic nitrile moiety, thereby disproving the proposed structure 2.