TOTAL SYNTHESIS OF PRIMNATRIENE-TYPE SESQUITERPENOIDS OF MARINE ORIGIN VIA REGIOSELECTIVE HALLER-BAUER CLEAVAGE OF ENDO-TRICYCLO(5.2.1.0(2,6))DECAN-10-ONE SYSTEM

Synthesis of densely functionalized aromatic sesquiterpenes 1 and 2a i solated from a marine organism and bearing an indan framework is repor ted. Tile key steps are the regioselective Haller-Bauer cleavage in an appropriately substituted endo-tricyclo(5.2.1.0(2,6))decan-10-one der ivative 4 and further build-up of functionalities on the bicyclic core prior to aromatization.