Stereoselective synthesis of Jaspine B and its C2 epimer from Garner aldehyde

Two different stereoselective routes for the synthesis of Jaspine B and its C2 epimer are presented here, starting from easily available Garner aldehyde. The key synthetic steps involved iodocyclization, organocuprate addition, HWE olefination, regioselective alpha-tosylation and cross metathesis reaction. This is the first report to synthesize Jaspine B involving iodocyclization.