The intramolecular nitrile oxide cycloaddition (INOC) route to the ergot alkaloids: Use of the isoxazoline to γ-amino alcohol conversion in the total synthesis of (+)-paliclavine
作者:Alan P. Kozikowski、Chen Yon-Yih、Wang B.C、Zhang-Bao Xu
DOI:10.1016/0040-4020(84)80018-6
日期:1984.1
A total synthesis of the ergot alkaloid paliclavine (20), in optically active form is described. The synthesis scheme is based on the intramolecular dipolar cycloaddition reaction of a nitrile oxide to a neighboring olefinic appendage bearing an allylic asymmetric center. The extent of diastereofacial selection in the intramolecular nitrile oxide cycloaddition (INOC) reaction was found to be marginal
描述了旋光形式的麦角生物碱青花石碱(20)的全合成。该合成方案基于腈的分子内偶极环加成反应与相邻的带有烯丙基不对称中心的烯烃附件。发现分子内一氧化氮环加成(INOC)反应中的非对面选择程度很小。单晶X射线分析已确定了由“主要” INOC产品制备的异恶唑啉15的完整立体结构。讨论了异恶唑啉鎓盐15a的还原立体化学对还原剂性质的依赖性。