Synthesis of substituted 3-methylene-2-pyridones from Baylis–Hillman derivatives and its application for the generation of 2-pyridone substituted spiroisoxazolines

The synthesis of substituted 3-methylene-2-pyridones via SN2 displacement reaction of nucleophiles bearing a keto group on the acetyl derivative of Baylis–Hillman adducts of acrylonitrile followed by TFA/H2SO4-mediated intramolecular cyclization is described. The utility of these pyridone derivatives for the synthesis of new spiroisoxazolines in highly regio- and stereo-selective fashion is also illustrated. The structure of the spiroisoxazolines has been secured via X-ray crystallographic analysis.