Stereoselective Synthesis of Freidinger Lactams Using Oxaziridines Derived from Amino Acids
作者:Michael S. Wolfe、Dinah Dutta、Jeffrey Aubé
DOI:10.1021/jo961670j
日期:1997.2.1
Conformationally restrained dipeptidyl lactams are building blocks for the synthesis of peptidomimetics, including Freidinger lactams (Figure 1). Few synthetic methodologies toward such moieties allow for incorporation of a stereodefined substituent on the ring nitrogen (i.e., corresponding to an amino acid side chain). Enantiopure Freidinger lactams were obtained by (1) condensation of (S)-tert-butoxycarbonyl
构象受约束的二肽基内酰胺是包括Freidinger内酰胺在内的拟肽模拟物的合成基石(图1)。针对这些部分的很少的合成方法允许在环氮上(即,对应于氨基酸侧链)引入立体定义的取代基。通过(1)将(S)-叔丁氧羰基(Boc)保护的2-氨基环烷酮与市售的α-氨基酯缩合获得对映纯的Freidinger内酰胺,(2)用m-CPBA氧化所得的亚胺以生成螺环型恶唑烷,以及(3)图像重排。描述了通过NMR和X射线晶体学对七元和八元二肽基内酰胺的构象分析。