Stereochemistry of sesquiterpenes of the germacrane type

An analysis has been made of the conformations of the 10-membered ring in the known sesquiterpene E,E-germacranes and a relationship has been established between the realization of one of the four conformers and the positions and orientations of substituents in the 10-membered ring. A relationship is presented between the conformational states of the germacrolides and the structures of their bicyclic derivatives — guaianes and eudesmanes.Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 497–506, July–August, 1997.