A novel synthesis of tricyclo [5.3.1.0^1^,^5]undecanes: Total syntheses of 2-norcedrene and a funebrene analogue

A new rearrangement method has been developed for the construction of the tricyclo[5.3.1.0(1.5)]undecane and tricyclo[6.3.1.0(1.6)]dodecane frame works. The key features include the efficient preparations of the alcohols 5, 15 and 19 and their rearrangement to the tricyclic skeleton which led to the synthesis of 2-norcedrene 3 and an analogue of funebrene 13