Facile Access to Cyclopentadienes via Catalytic Intramolecular Palladium-Ene Reaction of 2,4-Pentadienyl Acetates.

We have recently disclosed a palladium-catalyzed Trost- Oppolzer type Alder-ene reaction of 2,4-pentadienyl acetates for the synthesis of highly substituted cyclopentadienes and cyclopentenefused aromatics. The overall transformation also represents an acid-free iso-Nazarov type cyclization. Herein, we provide the hypothesis and rationale behind this work, while highlighting the seminal contributions of Trost, Oppolzer and others towards the development of the palladium- ene reaction. [ABSTRACT FROM AUTHOR]