The analysis of mixtures using the 2-D INADEQUATE NMR technique

The potential of the 2-D INADEQUATE NMR experiment for identifying differen t C-13/C-13 connectivities and distinguishing between signals of compounds with very similar structures is demonstrated for two mixtures: quinoline an d 3-acetyl pyridine, and n-propanol and 1,2-propanediol, and for the isomer ic forms of the two disaccharides: cellobiose and maltose. The 1-D C-13 NMR spectrum of the first mixture has features very similar to that of pyridin e, whereas the second mixture shows absorptions characteristic of tetrahydr ofuran, however the INADEQUATE experiment clearly distinguishes between pyr idine and tetrahydrofuran and the two mixtures. For cellobiose and maltose, 22 and 23 separate signals have been assigned respectively to specific car bon nuclei of the alpha and beta anomers. (C) 1999 Elsevier Science B.V. Al l rights reserved.