Efficient Synthesis of Benzofurans Utilizing [3,3]-Sigmatropic Rearrangement Triggered byN-Trifluoroacetylation of Oxime Ethers: Short Synthesis of Natural 2-Arylbenzofurans
作者:Norihiko Takeda、Okiko Miyata、Takeaki Naito
DOI:10.1002/ejoc.200601001
日期:2007.3
synthetic method for the preparation of benzofurans has been developed. The key step of this method is the [3,3]-sigmatropic rearrangement of N-trifluoroacetyl-ene-hydroxylamines, which was triggered by acylation of oxime ethers. TFAA has been proved to be the best reagent to induce [3,3]-sigmatropic rearrangement for the synthesis of cyclic oracyclic dihydrobenzofurans. On the other hand, the TFAT-DMAP