苯甲酰基二肽甲基酯的非对映异构体形式的1 H nmr光谱中的不同甲酯信号为估算非对映异构体混合物的异构体组成提供了一种手段。使用这种核磁共振技术对衍生自肽偶联反应的混合物进行分析,为比较一系列偶联试剂的消旋潜力提供了便利的方法。在模型肽偶联过程中,显着的不对称诱导伴随着外消旋作用。已使用13 C nmr光谱研究了构象效应,并已合理化了在1 H nmr光谱中观察非对映异构酯信号的结构标准。
Assessment of racemisation in N-alkylated amino-acid derivatives during peptide coupling in a model dipeptide system
作者:John S. Davies、A. Karim Mohammed
DOI:10.1039/p19810002982
日期:——
analysis of diastereoisomeric benzoyl dipeptide esters has been used to monitor racemisationduring the coupling of benzoyl-N-alkylated amino-acids to alanine and valine methyl esters. Results confirm the greater susceptibility of these amino-acids to racemisation, but conditions have been found which eliminate racemisation. The additives HONSu and HOBt vary in their capability as ‘chiral stabilisers’