The Chemistry of Laurenene. XIV. New Rearrangements of a Ring A Seco Ester

Abstract

Adsorption on neutral alumina of a keto ester derived from the diterpene lauren-1-ene has been shown to yield a new keto ester with an unusual bridged tricyclic ring system. With trifluoroacetic acid, both keto esters yield a further new compound which contains a benzene ring. The transformations involved may be rationalized in terms of carbocationic rearrangements. An alcohol derived from the compound with the bridged tricyclic ring system has been converted into a cyclopentacyclononene derivative by β -cleavage of the alkoxy radical.