The zwitterionic intermediate, generated by the addition of triphenylphosphane to dimethyl acetylenedicarboxylate, undergoes facile addition to ortho- and para-quinones to afford highly functionalized novel unsaturated γ-spirolactones in moderate to high yields.
由
三苯基膦与二甲基
乙炔二
羧酸酯反应生成的两性离子中间体,容易与邻位和对位醌发生加成反应,得到高功能化的新型不饱和γ-螺环内酯,产率中等到较高。