[Xacrifeol]

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Formula is C6H12O and is aliphatic.
I've been trying to figure out how to get a quartet of a quartet, but the only thing that comes to mind is a CH joined to 3 CH3 of different chemical environments, but I don't know how one can even get CH3 of different chem environments. D:

Also, I have totally no idea what the signal on the left most is supposed to be. Help please? ><

[Dan]

I've been trying to figure out how to get a quartet of a quartet, but the only thing that comes to mind is a CH joined to 3 CH3 of different chemical environments, but I don't know how one can even get CH3 of different chem environments. D:

I think you're barking up the wring tree with that one. I don't think it is a qq, it looks more like a qdd (quadrouple double doublet) to me. Notice that the each set of 4 peaks have the same intensity - suggestive of a dd rather than a q (which would give a 1:3:3:1 pattern).

Now, take note of the magnitude of the coupling constants of the dd. They are small, which is suggestive of long range coupling frequently encountered with a functional group that has signals in the 5-7 ppm range...

Do you have integrals? By eye I'd guess:

5.5 ppm 2H
3.7 ppm 1H
3.6 ppm 2H
2.2 ppm 2H
2.0 ppm 2H
1.1 ppm 3H

Is that right?

[Xacrifeol]

What's a qdd? @_@ As far as I understand, a doublet of a doublet is when a set of H gets influenced by 2 sets of H of different chemical environments. So a quadruple of a doublet of a doublet is... 4 sets of H getting influenced by 2 sets of H of different chem environments? D: I'm confused how it works when it's 3 layers. @_@

Also, what is long range coupling? :x Alkenes?

And nope I'm not given the integrals... D:

[Dan]

What's a qdd?

quadrouple double doublet

As far as I understand, a doublet of a doublet is when a set of H gets influenced by 2 sets of H of different chemical environments.

Yes. A double doublet is seen when the signal is coupling to 2 x inequivalent 1H.

So a quadruple of a doublet of a doublet is... 4 sets of H getting influenced by 2 sets of H of different chem environments?

I don't follow you here.

A quadrouple double doublet is seen when the signal is coupling to 1 x 3H and 2 x inequivalent 1H

Also, what is long range coupling? :x Alkenes?

Long range coupling is coupling through >3 bonds. It is common to see coupling through 4 bonds in alkenes (in addition to the usual 3 bond couplings).

[Xacrifeol]

Alright I kind of get it. :x So what would the leftmost signal be? It doesn't look like any coupling that I've learnt before. :x

[critzz]

I'm a little late to answer, but I'd still like to post my suggestion. 



First of all the structural formula indicates that the molecule only contains one unsaturation.
The 2H peak at 5.5 ppm also tells that the unsaturation is an alkene functionality.
The long range coupling through the double bond gives nice (but complex) splitting patterns.
Since the two protons in the methylene group are extremely similar in this case, the signals overlap.
I think it's an ABX system, which gives rise to second order effects ( the four tiny surrounding peaks at 5.5 ppm).

Furthermore, the broad signal at 4.7 ppm indicates the presence of an alcohol functionality.
There is also a CH₂-CH₂- fragment present, corresponding to the triplet at 1.1 ppm.
Finally, a HO-CH₂-CH₂- fragment is present, judging from the triplet at 3.5 ppm.

This is what the structure looks like when the fragments are put together logically.