Dearomatization of furans via [2,3]-Still–Wittig rearrangement
摘要:
Furans and benzofurans of type 1 were dearomatized via the [2,3]-Still-Wittig rearrangement. Enol ethers 2 could be isolated or isomerized to the corresponding furans 3. The substitution pattern at the homofuranylic position had a strong influence on reaction behaviour. Benzofurans rearranged with the greatest efficiency, and employment of a 3-substituted benzofuran (1; R'=CH3) allowed the creation of a quaternary carbon center. (C) 2004 Elsevier Ltd. All rights reserved.