A General Approach from Eudesmane to Isodaucane Sesquiterpenes: Synthesis of 7-Epi-14-isocyano-isodauc-5-ene from α-(-)-Santonin

A general and efficient approach for synthesis of an isodaucane sesquiterpenes has been developed by use of a novel and key rearrangement of a eudesmane enol ester epoxide. As an example, the 7-epi-14-isocyano-isodauc-5-ene has been successfully synthesized by a series of transformations from α-(-)-santonin.