Dearomatization of furans via [2,3]-Still–Wittig rearrangement

Furans and benzofurans of type were dearomatized via the [2,3]-Still–Wittig rearrangement. Enol ethers could be isolated or isomerized to the corresponding furans . The substitution pattern at the homofuranylic position had a strong influence on reaction behavior. Benzofurans rearranged with the greatest efficiency, and employment of a 3-substituted benzofuran (; R′=CH3) allowed the creation of a quaternary carbon center.