Q87 · CSIR-NET Chemistry, December 2015
Paper: CSIR-NET December 2015 · Subject: Organic Chemistry · Chapter: Organic Spectroscopy · Topic: NMR 1H · Marks: 2 · Difficulty: Medium
The number of chemical shift non-equivalent protons expected in $\mathrm{1H} ~ N M R$ spectrum of $\alpha-$ pinene is 
$\alpha$-pinene
$\alpha$-pinene(a)7
(b)8
(c)9
(d)10
Answer
Answer: D ✓ checked by 4AB · confidence medium
The source book printed B; on checking, D is correct — see the explanation.
Explanation
α-Pinene: three methyl singlets, the vinyl H, the two bridgehead CH, and the two CH₂ groups whose protons are diastereotopic (2 + 2): 3 + 1 + 2 + 4 = 10 inequivalent proton environments.
Study loop for Organic Spectroscopy