The Synthesis of a Dicyclopenta[<i>a</i>,<i>e</i>]pentalene via a Molybdenum Hexacarbonyl-Mediated Tandem Allenic Pauson−Khand Reaction

An approach to the 14π annulene has been developed, by employing the molybdenum hexacarbonyl-mediated tandem allenic Pauson−Khand reaction as a key step. A di-triisopropylsilyl substituted dicyclopenta[<i>a</i>,<i>e</i>]pentalene was synthesized. This 14π annulene showed some electronic delocalization, which was not observed in previous cases.