<i>N</i>-Heterocyclic Carbene Catalyzed Ring Expansion of Formylcyclopropanes: Synthesis of 3,4-Dihydro-α-pyrone Derivatives
作者:Gong-Qiang Li、Li-Xin Dai、Shu-Li You
DOI:10.1021/ol9002898
日期:2009.4.2
N-Heterocyclic carbene catalyzed ring expansion of readily accessible 2-acyl-l-formylcyclopropanes was developed. With 5 mol % of triazoliurn salt 5 and 30 mol % of DBU, ring expansion of various 2-acyl-l-formylcyclopropanes led to 3,4-dihydro-alpha-pyrones in good to excellent yields.