in-4-ones react as dienophiles on the exo-cyclic ylidene bond to give spiro-derivatives and as 1,3-dienes with olefins to give dihydropyranothiazole derivatives. The endo-cyclic CN bond in these compounds do not enter into the cycloaddition reactions.
2-聚氟烷基-5-甲氧基羰基亚甲基-
噻唑啉-4-酮以亲二烯体的形式在环外亚环基键上反应生成螺环衍
生物,并以1,3-二烯与烯烃的反应生成二氢
吡喃并
噻唑衍
生物。这些化合物中的环内CN键不参与环加成反应。