Capnellenols are series of sesquiterpenes isolated from soft coral Capnella imbricata. They posses unusual linear triquinane skeleton and biological activity. In this paper the key intermediate for the synthesis of Capnellenols

4

7

7 trimethylbicyclooctanone was synthesized with a five step route. The reaction conditions or methods of the four steps of this route were improved

and the results were satisfactory.