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Topic: Could this be the structure?  (Read 3579 times)

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Offline Petahit

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Could this be the structure?
« on: August 02, 2015, 11:07:18 AM »
Hi!
I have this spectroscopy problem. I have calculated the formula to be C11H14O3(hope it is right!), and I think I found the structure for this compund, but the peek at 1,4 of H NMR confuses me. So I am not sure if I am right or not... See my attempt drawing and major conclsions. Maybe I am missing something?

Thanks on beforehand.

Offline discodermolide

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Re: Could this be the structure?
« Reply #1 on: August 02, 2015, 11:13:41 AM »
Look at the NMR expansion you provided. It shows two different quartets for two different CH2 groups coupled to to different CH3 groups.
So the peaks are two triplets very similar in chemical shift, for the ester and the ether CH3 groups.
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Offline Petahit

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Re: Could this be the structure?
« Reply #2 on: August 02, 2015, 12:17:56 PM »
Look at the NMR expansion you provided. It shows two different quartets for two different CH2 groups coupled to to different CH3 groups.
So the peaks are two triplets very similar in chemical shift, for the ester and the ether CH3 groups.

Thank you, I understand that. But it is the peak at 1,4 that I do not really understand. Its integral(3) says that 3 H should have four neighbouring H. But there is no such way to draw the molecule(?). Or is it four neibours in total for the whole molecule, if you understand what I mean?

Offline discodermolide

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Re: Could this be the structure?
« Reply #3 on: August 02, 2015, 12:55:45 PM »
You have two triplets very close together. You have two different CH3 groups in your molecule, one attached to an ester and the other to an ether. This matches for the structure you drew.
The integral is not on the spectrum you posted but it should be for 6H.
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Offline Petahit

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Re: Could this be the structure?
« Reply #4 on: August 02, 2015, 01:43:49 PM »
You have two triplets very close together. You have two different CH3 groups in your molecule, one attached to an ester and the other to an ether. This matches for the structure you drew.
The integral is not on the spectrum you posted but it should be for 6H.

I now understood that peak at 1,3. Thank you so much for your *delete me*

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