Palladium-Catalysed Isomerisation of 2-Vinylidenehydrofurans to 1,3-Dienes and Some Aspects of Their Reactivity

The transformation of easily accessible 2‐vinylidenehydrofurans into stable 1,3‐dienes has been achieved by using catalytic amounts of palladium(0). These valuable compounds were then engaged in subsequent Diels–Alder reactions giving access to complex heterocyclic cores found in numerous natural products. A rationale for the regioselectivity of the Diels–Alder reactions with vinylfurans has been provided by DFT calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) Palladium has been employed as an efficient catalyst in the isomerisation of easily synthesised vinylidenehydrofurans to the corresponding 1,3‐dienes. When treated with dienophiles, these stable compounds afforded the expected Diels–Alder adducts in good yields and high diastereoselectivities.