Total Synthesis of (-)-Cinatrin C1 Based on an In(OTf)3-Catalyzed Conia-Ene Reaction

The stereocontrolled total synthesis of (-)-cinatrin C-1, a phospholipase A(2) inhibitor, has been accomplished. The key feature includes the stereoselective construction of the highly substituted tetrahydrofuran core by In(OTf)(3)-catalyzed Conia-ene reaction of the oxygen-tethered acetylenic malonic ester followed by dihydroxylation with concomitant lactonization.