作者:Stanimir Popovic、Linda Wijsman、Iris R. Landman、Maaike F. Sangster、Dorien Pastoors、Berend B. Veldhorst、Henk Hiemstra、Jan H. van Maarseveen
DOI:10.1002/ejoc.201501366
日期:2016.1
difficult lactamizations are accompanied by side-reactions such as hydrolysis, oligomerization and racemization. By starting from linear peptide 4-methoxythiophenol esters, dilution to 1 mM in combination with phosphate buffer (pH 6.8) intermolecular reactions and racemization could be largely suppressed. Thioesters with the chiral residue at the C-terminus gave the bislactams in yields up to 60% and enantiomeric
对含有 - 氨基酸和 - 丙氨酸的七元双内酰胺的闭环是有问题的。这种困难的内酰胺化伴随着副反应,例如水解、低聚和外消旋。通过从线性肽 4-甲氧基苯硫酚酯开始,与磷酸盐缓冲液 (pH 6.8) 结合稀释至 1 mM,可以在很大程度上抑制分子间反应和外消旋化。在 C 端具有手性残基的硫酯以高达 60% 的产率和高达 99% 的对映体过量得到双内酰胺。对映体纯双内酰胺仅从 C 端带有丙氨酸的反向序列中获得。