作者:Christoph Hermann、Godwin C.G Pais、Armin Geyer、Sven M Kühnert、Martin E Maier
DOI:10.1016/s0040-4020(00)00772-9
日期:2000.10
instead of the α-hydroxy acid. In this case, however, the cyclization with the Shioiri reagent induced a Curtius rearrangement prior to the cyclization reaction. As a result the two ring expanded hapalosin analogs 29 and 30 were formed. The conformations of the three macrocycles were studied by 2D NMR spectroscopy and molecular dynamics simulation. It was found that in DMSO-d6 all of them prefer the
大环二肽肽Hapalosin由三个亚基组装而成。从受保护的β-羟基酸13与α-羟基酯14的缩合开始,产生羟基二酯16。该化合物继而与γ-氨基-β-羟基酸17缩合。对完全脱保护的氨基酸20进行大环化。以类似的方式,制备了包含缬氨酸而不是α-羟基酸的环化基质28。但是,在这种情况下,在环化反应之前,用Shioiri试剂进行环化会引起Curtius重排。结果,两个环扩展了碱性磷酸酶类似物29和30个形成了。通过2D NMR光谱和分子动力学模拟研究了三个大环的构象。发现在DMSO- d 6中,它们所有人都更喜欢叔酰胺周围的s-反式-酰胺旋转异构体。