FACILE SYNTHESIS OF [5.n.1.01,5] TRICYCLES MEDIATED BY INTRAMOLECULAR PAUSON-KHAND REACTION: A FORMAL TOTAL SYNTHESIS OF CEDRENE TERPENOIDS　

24th International Symposium on the Chemistry of Natural Products and the 4th International Congress on Biodiversity　New Delhi (India)

  In our continuing studies on Pauson-Khand reaction (PKR) of exo-cyclic enynes,1 we examined synthesis of [5.n.1.01,5] tricyclic compounds (n = 2-4) by intramolecular PKR of various 3-alkynyl-1-alkylidenecyclic compounds. We applied the present reaction to formal total synthesis of α- and β-cedrenes.