The utility of the classical and oxidative Heck reactions in natural product synthesis: Studies directed toward the total synthesis of dragmacidin F

The syntheses of complex pyrrole-fased [3.3.1] and [3.3.2] bicycles using classical and oxidative Heck cyclizations are described. While both [3.3.1] and [3.2.2] bicyclic products are formed in the classical Heck reaction, the oxidative Heck cyclization reaction furnishes solely the [3.3.1] bicycle. The [3.3.1] bicyclic product has been used as an intermediate to synthesize the complex marine alkaloid dragmacidin F.