Cembranoids, Pseudopteranoids, and Cubitanoids of Natural Occurrence

The structures of (+)-cembrene (1), a macrocyclic diterpene hydrocarbon isolated from pine oleoresins (1, 2), and of the two epimeric cembratrienediols 35 and 36, which were obtained from tobacco (3), were reported in 1962. Since these pioneering studies, the structures of some 300 naturally occurring cembranoids have been resolved. These include both hydrocarbons and oxygen-containing compounds, the latter possessing e.g. epoxy, oxo, hydroxy and lactone functions. Many are polyoxygenated.