Facile and efficient constructions of the carbocyclic frameworks of four kinds of terpenoids from a common precursor

Abstract

Facile and efficient syntheses of the basic carbocyclic frameworks of stemodane [(7)], cedrane [(14) and (17)], perhydroazulene [(21)], and himachalene [(26)] terpenoids are described. The key features of the synthetic study were the use of the 2-hydroxytricyclo[6.3.1.0^1,6]dodec-4-en-12-one (2), which was readily obtained by a stereoselective intramolecular Diels–Alder reaction of the trienone (1), as a common precursor and use of simple manipulations for the construction of these terpenoid skeletons.