intramolecular [4+ 2] cycloaddition of a (phenylthio) acetylene–cobalt complex is described,
which is applicable for the asymmetric total synthesis of naturally occuring 1. The highlight of
this work is the aromatic Pummerer‐type reaction with 1‐ethoxyvinyl chloroacetate, which
effects the introduction of the oxygen functional group to the internal B‐ring of the highly
functionalized, congested polyaromatic ABC‐ring moiety.