Total synthesis of (S)-14-azacamptothecin†
Abstract
A concise synthesis of (S)-14-azacamptothecin has been accomplished in 8 steps from commercially available (R)-2-hydroxybutanoic acid. The key strategy involved in this synthesis is the Michael addition/β-elimination sequence to construct the chiral quaternary carbon center, followed by palladium catalyzed cyanation and formal [4 + 2] cycloaddition/elimination/aromatization in a one pot manner to form the pyrrolopyrimidin-4-one moiety.