Determination of the absolute configuration and enantiomeric purity of alcohols from the ¹³C‐NMR spectra of the corresponding MTPA esters

Abstract

From a study of the 13C-shift values of the MTPA esters of 3-substituted cyclohexanols of known absolute configuration an empirical rule has been developed to determine the absolute configuration of chiral cyclohexanols. The method is based on the Dale-Mosher model, which was originally developed for 'H-NMR spectra. The scope and limitations of this method are discussed. The enantiomeric purity of the alcohols can be determined simultaneously by integration of the signals in well-resolved diastereotopic carbon pairs.

The Disorazole Z Family of Highly Potent Anticancer Natural Products from Sorangium cellulosum: Structure, Bioactivity, Biosynthesis, and Heterologous Expression

“…X-ray analysis revealed the relative configuration of disorazole Z1 (compound 3). In order to elucidate the absolute configuration, Mosher’s method based upon 1 H and 13 C NMR chemical shift differences was applied ( 28 – 31 ). Consequently, all asymmetric centers ( 12 , 25 , 26 ) of compound 3 are in the S configuration, as shown in Fig.…”