Organocatalytic enantioselective oxa-Piancatelli rearrangement.

The first highly enantioselective oxa-Piancatelli rearrangement has been developed. This process which is catalyzed by a chiral BINOL-derived phosphoric acid rearranges a wide range of furylcarbinols into densely substituted γ-hydroxy cyclopentenones in high yield with excellent diastereo- and enantioselectivities (up to 99 : 1 er). This reaction exhibits a high functional group tolerance and was applied to complex bioactive molecules as well. The products were further manipulated into value-added molecular scaffolds further highlighting their versatility and synthetic utility.