Oxidative Coupling of (-)-Sclareol and Related Diols Leading to Oxepane Terpenoids.

Treatment of (-)-sclareol and related compounds with lead tetraacetate affords tetracyclic compounds bearing a 2,8-dioxabicyclo[5.2.0]nonane moiety with complete regio- and stereoselectivity. This process, which is also applicable to 1,5-diols with a similar substitution pattern, facilitates the development of efficient syntheses toward oxepane terpenoids, such as aplysistatin derivatives.