Synthesis of the Griseusin A ring system
Abstract
An efficient synthesis of the pentacyclic framework (12) of the pyranonaphthoquinone antibiotic Griseusin A (1) is reported. The key step involves assembly of the furo[3,2-b]naphtho[2,3-d]pyran (11) ring system via a ceric ammonium nitrate oxidative rearrangement of the furo[3,2-b]naphtho[2,1-d]furan (10).