Question

Compound C has a molecular ion in its mass spectrum at 146 and a prominent absorption in its IR spectrum at 1762 \({\bf{c}}{{\bf{m}}^{{\bf{ - 1}}}}\). C shows the following \(^{\bf{1}}{\bf{H}}\) NMR spectral data: 1.47 (doublet, 3 H), 2.07 (singlet, 6 H), and 6.84 (quartet, 1 H) ppm. What is the structure of C?

Short answer

Mass spectrometry is used to determine the structure through the formation of the molecular ion. It also forms the stable fragments of the molecules and determines the m/z values.

Step-by-step solution

Mass spectrometry

Mass spectrometry is used to determine the structure through the formation of the molecular ion. It also forms the stable fragments of the molecules and determines the m/z values.

Step 2: \(^{\bf{1}}{\bf{H}}\) NMR

The\(^{\rm{1}}{\rm{H}}\)NMR gives the location of the non-equivalent protons. The formula to calculate the number of peaks is\({\rm{n + 1}}\).

For example, the methyl protons split the adjacent protons into a quartet.

Explanation

IR absorption at 1762\({\rm{c}}{{\rm{m}}^{{\rm{ - 1}}}}\): C=O

NMR data: 1.47 (doublet, 3 H, \({\rm{C}}{{\rm{H}}_{\rm{3}}}\) group), 2.07 (singlet, 6 H, 2\({\rm{C}}{{\rm{H}}_{\rm{3}}}\)), and 6.84 (quartet, 1 H) ppm