Conformational analysis of methylsuccinic acid by 1H NMR spectroscopy and circular dichroism |
| |
| Authors: | János Rétey William E Hull Feliska Snatzke Günther Snatzke Ulrich Wagner |
| |
| Institution: | Lehrstuhl für Biochemie im Institut für Organische Chemie der Universität Karlsruhe, Richard-Willstätter Allee, 7500 Karlsruhe, Germany;Bruker Analytische Messtechnik GmbH, Am Silberstreifen, 7512 Rheinstetten 1, Germany;Lehrstuhl für Strukturchemie, Ruhr-Universität Bochum, Universitätstraße 150, 4630 Bochum, Germany |
| |
| Abstract: | The pH-dependence of the 1H NMR and Circular Dichroism (CD) spectra of 2-methylsuccinic acid was investigated. Both spectra undergo dramatic changes between pH 4 and 6, where both carboxylic groups become ionized. From the coupling constants of the tertiary proton with the assigned1 diastereotopic methylene protons, it is concluded that below pH 4 the syn-clinal (2) and above pH 6 the anti-periplanar (1) conformation of methylsuccinic acid prevail. The diesters of methylsuccinic acid also assume mainly the syn-clinal conformation (2). The pH-dependence of the CD spectra is discussed in terms of conformation and/or ionization effects. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
