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。
Syntheses of hapalosin analogs by solid-phase assembly of acyclic precursors
作者:Christoph Hermann、Chiara Giammasi、Armin Geyer、Martin E Maier
DOI:10.1016/s0040-4020(01)00903-6
日期:2001.10
The paper details the synthesis of hapalosin analogs 4 (cyclic depsipeptides) using solid-phase chemistry. Key building blocks were the Fmoc-protected γ-amino-β-hydroxy acid 11 and the THP-protected syn-β-hydroxy acids 18. The amino acid 11 was fashioned from the amine 6 which was obtained by an ADH-route. The protected amino acids 18 were prepared by Evans aldol reactions. Esterification of 18 with