73.Gold-Catalyzed Rearrangement of Allylic Oxonium Ylides: Efficient Synthesis of Highly Functionalized Dihydrofuran-3-ones

Junkai Fu, Dr. Hai Shang, Zhaofeng Wang, Dr. Le Chang, Wenbing Shao, Prof. Dr. Zhen Yang, Prof. Dr. Yefeng Tang

Angew. Chem. Int. Ed. 2013, 52, 4198

“Diazo” not needed: The title reaction results in the rearrangement of oxonium ylides, which were prepared from readily available homopropargylic allylic ethers instead of diazo compounds, through two different mechanisms: a concerted 2,3-sigmatropic rearrangement, or a stepwise 1,4-allyl migration followed by a Claisen rearrangement (see scheme).