Heteroatom-directed Wacker oxidations. A protection-free synthesis of (-)-heliophenanthrone

The first enantioselective six-step synthesis of (-)-heliophenanthrone has been achieved without any protection-deprotection protocol at an overall yield of 28%. Key features of this synthesis comprise a heteroatom-directed Wacker oxidation of an internal cyclic olefin in addition to asymmetric Brown allylation and ring closing metathesis (RCM).