Q101 · CSIR NET Chemistry, December 2019
Paper: CSIR NET December 2019 · Subject: Organic Chemistry · Chapter: Organic Spectroscopy · Topic: NMR 1H · Marks: 2 · Difficulty: Easy
The natural product that gives a signal at 218 ppm in its ${ }^{13} \mathrm{C} \mathrm{NMR}$ spectrum is
(a)$\alpha$-pinene
(b)camphor
(c)geraniol
(d)carvones
Answer
Answer: B ✓ checked by 4AB · confidence high
The source book printed D; on checking, B is correct — see the explanation.
Printed D; carvone's carbonyl is conjugated and appears near 199 ppm.
Explanation
δ 218 is a saturated ketone carbonyl — camphor; carvone's conjugated enone is near 199, and the others have no C=O.
Study loop for Organic Spectroscopy