Enantioselective synthesis of phomallenic acid C by In- and Pd-mediated anti-SN2′ coupling

Enantioselective synthesis of phomallenic acid C, an inhibitor of bacterial FAS II pathway, was succeeded. Allenyldiyne structure was constructed by a direct anti-SN2′ coupling of propargyl mesylate with diynylindium in the presence of palladium catalyst. Enantiomeric purity was determined by Ohrui-Akasaka method to be 96% ee.