An intramolecular Pauson–Khand approach to the synthesis of chiral cyclopentadienes

A procedure for the synthesis of chirally-substituted cyclopentadienes has been developed by employing the intramolecular Pauson–Khand reaction of chiral amides derived from 8-nonen-2-ynoic acid. Hydride-mediated reduction of the resulting cyclopentenone adducts followed by acid-catalysed dehydration leads to the formation of the corresponding cyclopentadienes in good overall yield.