The proton NMR spectrum of an unknown compound contains a triplet at 9.8 ppm. Which of the following could be this unknown?

Question

Quizplus · Accepted Answer

The triplet at 9.8 ppm indicates a proton split into three peaks by two equivalent neighboring protons. In compound C, there are two methyl groups (CH3) attached to a methylene (CH2) group, which is attached to a carbonyl group (C=O). The methylene protons can split the methyl protons into a triplet, resulting in a peak at around 9.8 ppm. None of the other compounds have this arrangement of groups and are therefore unlikely to give a triplet at 9.8 ppm.

The Proton NMR Spectrum of an Unknown Compound Contains a Triplet