Total syntheses of (+)- and (-)-pestalotiopsin A

Enantioselective total synthesis of both enantiomers of caryophyllene-type sesquiterpenoid pestalotiopsin A is achieved, thus indicating the absolute stereochemistry of natural (+)-pestalotiospin A. The highlights of the synthesis have included the [2+2] cyloaddition of N-propioloyl Oppolzer's camphorsultam and ketene dialkyl acetal and a palladium-catalyzed reduction of allylic mesylate with retention of the E configuration.