13C NMR spectral behavior of N-substituted-4-piperidones in methanol. Possibility of distinguishing between acetal and hemiacetal.
作者:CHISAKO YAMAGAMI、MAKIKO SUGIURA、KAZU TAMURA、NARAO TAKAO
DOI:10.1248/cpb.28.2653
日期:——
The behavior of several N-substituted-4-piperidones in methanol has been studied by 13C nuclear magnetic resonance (NMR) spectroscopy. All the piperidones studied were found to be equilibrium with their hemiacetals in methanolic solutions. The features of N-acyl derivatives were different from those of N-alkyl derivatives and the differences could be accounted for by electronic factors. The chemical shifts of the acetals were also determined and a procedure for distinguishing between hemiacetal and acetal is proposed.
通过 13C 核磁共振 (NMR) 光谱研究了几种 N-取代-4-哌啶酮在甲醇中的行为。发现所有研究的哌啶酮在甲醇溶液中与其半缩醛达到平衡。 N-酰基衍生物的特征与N-烷基衍生物不同,这种差异可以通过电子因素来解释。还测定了缩醛的化学位移,并提出了区分半缩醛和缩醛的程序。