KCS

While 3-oxidopyrylium ions are well-known for its [5+2] cycloaddition reaction with dipolarophile and the reaction has been widely used to synthesize natural compounds having 7-membered ring, dimerization reaction of 3-oxidopyrylium ions through [5+3] cycloaddition to form cyclooctanoids has not been used in total synthesis presumably due to dense functionalization around the product. Herein, we report the first application of the dimerization of 3-oxidopyrylium ions in the total synthesis of natural product. We accomplished the first total synthesis of a cyclooctanoid natural product, jujuyane that possesses 5 stereocenter and α-methylene lactone.