Expeditious Total Syntheses of Natural Allenic Products via Aromatic Ring Umpolung

Concise diastereoselective syntheses of the marine (±)-panacene and terrestrial (±)-desbromopanacene have been achieved in a few steps based on a concept of “aromatic ring umpolung”. The synthetic avenue to the (±)-panacene involved a novel oxymercuration strategy to produce the correct configuration of the bromoallene moiety.