An Improved Diastereoselective Synthesis of Spiroazoles Using Multicomponent Domino Transformations
作者:Francesco Risitano、Elisa Altieri、Massimiliano Cordaro、Giovanni Grassi、Angela Scala
DOI:10.1055/s-0030-1258516
日期:2010.9
Spiroisoxazole and spiropyrazole derivatives were obtained in a four-component reaction of active isoxazol- or pyrazol-5-ones with aromatic aldehydes, phenacyl chloride and AcOH-AcONH4 mixture. The reaction sequence is highly chemo- and diastereoselective affording good yields of spiroisoxazoles in refluxing ethanol, while efficient formation of spiropyrazoles is closely related to the use of a microwave-assisted protocol.
活泼异恶唑-或吡唑-5-酮与芳香醛、苯乙酰氯和乙酸-乙酸铵混合物通过四组分反应,合成了螺异恶唑和螺吡唑衍生物。反应序列具有高度的化学选择性和立体选择性,在回流乙醇中可获得产率良好的螺异恶唑,而高效合成螺吡唑则密切依赖于微波辅助方案的使用。