involves the chelation between the amido group and aldehyde oxygen by SnCl4, and the Felkin–Anh model by BF3·OEt2. The resulting allylation products were used for the total syntheses of tetraacetyl d-lyxo-, d-ribo-, and d-arabino-phytosphingosines. The stereoselective allylations of β-amino-α-hydroxy aldehydes are described. Several Lewis acids (BF3·OEt2, SnCl4, TiCl4, ZnCl2, and MgBr2·OEt2) were utilized
摘要 描述了β-
氨基-α-羟基醛的立体选择性
烯丙基化。在
烯丙基化中使用了几种
路易斯酸(BF 3 ·OEt 2,SnCl 4,TiCl 4,ZnCl 2和MgBr 2 · OEt 2 )。SnCl 4介导的抗-β-NHCbz-α-OTBS底物的
烯丙基化提供了顺选择性产物,而BF 3 ·OEt 2介导的其
烯丙基化则提供了抗选择性产物。的
烯丙基化顺通过介导的SnCl-β-NHCbz的制备-α-OTBS 4得到的反-选择性产品。其机理涉及SnCl 4
酰胺基与醛
氧的螯合,以及BF 3 ·OEt 2的Felkin-Anh模型。将得到的
烯丙基化产物用于四
乙酰基的总合成d - L-来苏- , - d -
核糖- ,和d -阿拉伯-phytosphingosines。 描述了β-
氨基-α-羟基醛的立体选择性
烯丙基化。在
烯丙基化中使用了几种
路易斯酸(BF 3 ·OEt 2,SnCl 4,TiCl 4,ZnCl 2和MgBr