作者:Michinori Waki、Johannes Meienhofer
DOI:10.1021/ja00460a039
日期:1977.8
permit solution synthesis’ of homogeneous peptides with up to 50 amino acid residues2 but condensation of peptides of this size to obtain proteins with over 100 residues has not yet progressed beyond the pioneering stage. The remarkable ribonuclease S-protein synthesis by Hirschmann et al.3 remains to be as yet the only preparation of a peptide of over 100 residues. This synthesis underscored the problem
通过合成受保护的二肽、三肽和四肽,研究了“四组分缩合”(4CC)或“Ugi 反应”在肽片段偶联中的应用。最合适的溶剂是醇类,包括甲醇、1-丁醇、三氟乙醇和六氟-2-丙醇,如 Ac-Gly-(N.Bzl-D~-Val~-Gly-OBu-f in 60 80% 产率。通过模型二肽 Pht-Gly-Gly-OR (R = H, Bu-f, Me) 和四肽 Z-Gly 的合成来检查几种醛在 4CC 片段缩合和随后辅助取代基的裂解中的功效-Ala-LeuGly-OR (R = H, Bu-f) 衍生物. 2-硝基苯甲醛 (光解), 2,4-二甲氧基苯甲醛, 1-rut-butyloxycarbonyl-3-formylindole (酸解), 和 4-吡啶甲醛(电解裂解)与环己基异腈一起被证明是有效的。例如,Z-Gly-Ala-Leu-Gly-OBu-f 是由 Z-Gly-Ala-OH 和 H-LeuGly-OBu-f