13C NMR EXAMPLES.......Ethyl cyanoacetate

C5H7O2N

. IUPAC Name: ethyl cyanoacetate   The peak is a singlet, indicating that it corresponds to a carbon bearing no hydrogens. The chemical shift (d 172) suggests that the carbon is a carbonyl, most likely a carboxylic acid or ester.       The peak is a singlet, indicating that it corresponds to a carbon bearing no hydrogens. The chemical shift (d 118) is in the region often observed for alkenes, alkynes adjacent to electron withdrawing groups and for nitriles.   The peak is a triplet, indicating that it corresponds to a CH2 group. The chemical shift (d 59) suggests that the CH2 is adjacent to an electronegative atom (i.e., oxygen). - O - CH2-     The peak is a triplet, indicating that it corresponds to a CH2 group. The chemical shift (d 22) suggests that the CH2 is adjacent to something mildly electronegative (i.e., a carbonyl), or is shielded by an adjacent sp-p system.        The peak is a quartet, indicating that it corresponds to a CH3 group. The chemical shift (d 14) is in the "simple" range, suggesting a simple terminal CH3 adjacent to something like a CH2. - CH2 - CH3     Analysis : Molecular formula and index of hydrogen deficiency C5H7O2N The index of hydrogen deficiency is 3, (3 degrees of unsaturation). Interpret : d (ppm) Multiplicity (n + 1) Indicating 172 singlet 118 singlet 59 triplet - O - CH2- 22 triplet 14 quartet - CH2 - CH3 ///////