Synthesis of Conformationally Restricted Cyclic Hexadepsipeptidesvia Direct Amide Cyclization
作者:Kristian N. Koch、Heinz Heimgartner
DOI:10.1002/1522-2675(20000809)83:8<1881::aid-hlca1881>3.0.co;2-g
日期:2000.8.9
in the synthesis of 19-membered cyclic depsipeptides 27 (Schemes1 and 3). The linear hexapeptide precursors 4, containing the beta-hydroxy acid 3-hydroxy-2-phenylpropanoic acid (Tro), and five alpha-amino acids of the type Aib, Gly, and Pro, were prepared according to Scheme 2. The alpha,alpha-disubstituted alpha-amino acid Aib was incorporated into the peptide chain via the azirine/oxazolone method
通过直接酰胺环化的环闭合用于合成 19 元环状缩肽 27(方案 1 和 3)。根据方案 2 制备线性六肽前体 4,包含 β-羟基酸 3-羟基-2-苯基丙酸 (Tro) 和 Aib、Gly 和 Pro 类型的五种 α-氨基酸。 α-二取代α-氨基酸Aib通过氮丙啶/恶唑酮法引入肽链,Gly和Pro通过TBTU/HOBt偶联法引入。环状缩肽 27a-27f 以合理至优异的产率获得(方案 3 和表 1)。