Novel Bicyclic Lactams as XaaPro Type VI β Turn Mimics: Design, Synthesis, and Evaluation
作者:Kyonghee Kim、Jean-philippe Dumas、Juris P. Germanas
DOI:10.1021/jo960012w
日期:1996.1.1
The design, enantioselective synthesis, and structural characterization of novel bicyclic lactams as peptide mimics of the type VI beta turn is described. The mimics duplicate the conformation of the backbone and disposition of the side-chain atoms of the central two residues of the turn. The Gly L-Pro mimic, lactam 6, was prepared in good overall yield starting from (S)-2-(2'-propenyl)proline. (1)H
描述了新型双环内酰胺作为VIβ型转弯肽模拟物的设计,对映选择性合成和结构表征。该模拟物复制了骨架的构型和该匝的中心两个残基的侧链原子的布置。从(S)-2-(2'-丙烯基)脯氨酸开始,以良好的总收率制备了Gly L-Pro模拟物内酰胺6。(1)1 H NMR光谱确定了内酰胺六元环的取代基的相对立体化学和构象特征;X射线晶体学分析证实了构象和立体化学分配。对内酰胺6的晶体结构的检查表明,中央酰胺键明显扭曲出平面度。酰胺键的扭曲归因于在两个环的交界处存在sp(2)-杂化氮原子而导致的角度应变。内酰胺6的N,N-二甲基甲am衍生物的烯醇化物与苄基溴的烷基化选择性地提供了甲am11,其为VI-turn构型的L-Phe L-Pro二肽的模拟物。高度合成的模拟肽(例如11)的有效合成途径将在肽结构功能研究中被证明非常有用。