作者:Guillaume Jeannotte、William D. Lubell
DOI:10.1021/jo049612i
日期:2004.7.1
the selective deprotection and alkylation of the pyrrole nitrogen of pyrroloprolines 17 were developed to expand the diversity of the heteoaryl systems. Finally, hydrogenolytic cleavage of the PhF and benzyl groups followed by subsequent protection with Boc, Fmoc, and Moz groups was performed to obtain analogues suitable for peptide synthesis. The enantiomeric purity of N-(Boc)pyrrolo-proline 21a was
按照以下两种方法,从4-氧代-N-(PhF)脯氨酸苄基酯(6,PhF = 9-(9-苯基芴基))制备熔融的杂芳基脯氨酸。首先,羟脯氨酸6的烯丙基化,然后进行Wacker氧化,得到1,4-二酮8,该1,4-二酮8被选择性地转化为吡咯啉脯氨酸10b,吡咯并吡咯12和哒嗪基脯氨酸9。第二,氧代脯氨酸6与一系列N-(Boc)-α-氨基醛15a - e的醛醇缩合和酸催化的环化反应得到吡咯啉脯氨酸17a - e具有各种吡咯5位取代基。开发了吡咯脯氨酸17的吡咯氮的选择性脱保护和烷基化条件,以扩大杂芳基系统的多样性。最后,进行PhF和苄基的氢解裂解,随后用Boc,Fmoc和Moz基团进行保护以获得适合于肽合成的类似物。N-(Boc)吡咯并脯氨酸21a的对映体纯度是通过与l-和d偶联来确定的-苯丙氨酸甲酯和非对映体吡咯质子的检查,证明二肽的非对映体纯度> 99%。因此,这些方法提供了第一批对映体纯的稠合芳