Total synthesis of (-)-cinatrin C1 based on an In(OTf)3-catalyzed Conia-Ene reaction.

The stereocontrolled total synthesis of (-)-cinatrin C1, a phospholipase A2 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.