Why is the NMR multiplicity incorrect in some places?

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SUMMARY

The discussion centers on the inaccuracies in NMR multiplicity assignments for carbon atoms in a molecular structure. Specifically, the participant identifies that carbon ##X##, with two neighboring hydrogens, should exhibit a triplet, while carbon ##Y##, with three neighboring hydrogens, should display a quartet. Additionally, carbon ##Z##, having no neighboring hydrogens, should present as a singlet. The consensus is that the assignment provided in the assignment is incorrect, corroborated by external sources.

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etotheipi
I was doing a question that wanted you to determine the structure given a molecular formula and an NMR spectrum. The following was the answer:
1583685998403.png

I'm unsure as to how the multiplicities were obtained. For ##X##, the neighbouring carbon ##Y## has 2 hydrogens, so this peak is a triplet (OK so far!).

But for ##Y##, the neighbouring carbon (##X##?) has 3 hydrogens so shouldn't that peak should be a quartet? And ##Z##'s neighbouring carbon has no hydrogens so this peak should just be a singlet. This also agrees with the integration, since both ##X## and ##Z## have 3 hydrogens but ##Y## only has 2. I am not sure why they have put it the other way around?

Thank you!
 
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I agree with you argumentation. It looks like the assignment is wrong.
 
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DrStupid said:
I agree with you argumentation. It looks like the assignment is wrong.

Ah, awesome. Vindication!
 
It’s wrong online in some places as well. This is the wrong assignment!
https://physics.bgu.ac.il/COURSES/LAB_C/NMR/htbooks/nmr/spectra/mek-016.gif
 
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