Modhephene: a sesquiterpenoid carbocyclic [3.3.3]propellane. X-Ray crystal structure of the corresponding diol

Modhephene (2), a new sesquiterpene representing the first naturally occurring carbocyclic [3.3.3]propellane, has been isolated from the toxic plant Isocoma Wrightii; its structure was confirmed by X-ray analysis of the corresponding diol (3).