Total Synthesis of (+)-Sch 725680: Inhibitor of Mammalian A–, B–, and Y–Family DNA Polymerases

The total synthesis of (+)-Sch 725680, a member of the hydrogenated azaphilone family, has been accomplished. The synthesis confirmed the absolute configuration and biological activities of the natural product. A key reaction to construct a hydrogenated azaphilone core skeleton is a Ti-mediated aldol reaction.