Cycloaddition of aldehyde and ketone oximes are shown to give mixtures of all possible isoxazolidine regioisomers and stereoisomers. The products are 2 : 1 adducts with the second molecule of the di-polarophile attached to the isoxazolidine N-atom. The stereochemistry of the major isomer from benzaldehyde oxime and acrylonitrile was established by an X-ray crystal structure analysis. The cycloaddition
醛和
酮肟的环加成显示出所有可能的
异恶唑烷区域异构体和立体异构体的混合物。产物是2:1的加合物,其第二亲双性分子附着在
异恶唑烷的N-原子上。通过X射线晶体结构分析建立了
苯甲醛肟和
丙烯腈的主要异构体的立体
化学。环加成反应被
2,4-
二硝基苯酚弱催化,在
乙腈中进行得最好。更多极性溶剂稍微偏爱5-
异恶唑烷区域异构体。讨论了反应机理。