Total Synthesis of the C-1027 Chromophore Core:Extremely Facile Enediyne Formation through SmI2-Mediated 1,2-Elimination

摘要

The antitumor antibiotic C-1027 is a complex between the reactive chromophore 1(Scheme 1)and an apoprotein.The chromophore 1 is responsible for DNA recognition and damage,and the apoprotein functions as an effective drug-delivery system.As the free chromophore,1 is the most labile enediyne studied to date:It is transformed into 3 in 82% yield by Masamune-Bergman rearrangement and subsequent hydrogen abstraction(ethanol,25 °C)with a half-life of 50 min.