Efficient Synthesis of Benzofurans Utilizing [3, 3]??Sigmatropic Rearrangement Triggered by N??Trifluoroacetylation of Oxime Ethers: Short Synthesis of Natural 2?? …

N Takeda, O Miyata, T Naito

Index: Takeda, Norihiko; Miyata, Okiko; Naito, Takeaki European Journal of Organic Chemistry, 2007 , # 9 p. 1491 - 1509

Full Text: HTML

Citation Number: 67

Abstract

Abstract A new 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 system is found to be ...