18α-Olean-12-ene, which is in acid-catalysed equilibrium with olean-13 (18)-ene (δ- amyrene), has been converted in several steps into olean-12-ene (β-amyrene). Transformation of this hydrocarbon into its 11α-hydroxyderivative and photolysis of the nitrite of the latter gave 11α-hydroxy-1-oximino-olean-12-ene. This oxime has been hydrolysed and further processed to furnish olean-12-en-1-one. Several methods have been ...
