1,2,3-Trisubstituted cyclopropanes as conformationally restricted peptide isosteres: application to the design and synthesis of novel renin inhibitors
作者:Stephen F. Martin、Richard E. Austin、Christopher J. Oalmann、William R. Baker、Stephen L. Condon、Ed DeLara、Saul H. Rosenberg、Kenneth P. Spina、Herman H. Stein
DOI:10.1021/jm00088a005
日期:1992.5
greater than or equal to 94% enantiomeric excess. Nucleophilic opening of the lactone ring of 12a-d gave the corresponding morpholine amides 14a-d. By exploiting tactics that allowed for selective epimerization of one of the two functionalized side chains on the cyclopropane nucleus, 14a-d were transformed into the two series of diastereoisomeric morpholine amide carboxylic acids 15a-d and 18a-d. Epimerization
1,2,3-三取代的环丙烷6和7是肽连接的新型等位取代的第一类成员,肽连接通常由二肽模拟物2和3代表。这些独特的肽替代物专门设计用于锁定一个区域以扩展的β-链构象(phi-角度限制)形成肽主链,同时对氨基酸侧链实施两个明确定义的取向之一(x 1角度限制)。首先开发了一种以Rh2(S-MEPY)4为特征的有效方法,用于立体选择性,不对称合成三取代环丙烷15a-d,18a-d,22a-d和23a-d(方案II)的方法(11 )和Rh2(R-MEPY)4(20)催化烯丙基重氮乙酸酯10a-d的环化反应,分别得到旋光内酯12a-d和21a-d,对映体过量大于或等于94%。12a-d的内酯环的亲核开环得到相应的吗啉酰胺14a-d。通过利用允许在环丙烷核上的两个官能化侧链之一进行选择性差向异构化的策略,将14a-d转变为两个系列的非对映异构吗啉酰胺羧酸15a-d和18a-d。14a-d发生吗啉酰胺基的