[Telamond]

So I made 4-methyl-1-penten-3-ol.
I've attached the ¹H-NMR I received from it.
In the report I wrote this:

¹H-NMR (400 MHz; CDCl3): δ 5.86 (1H, ddd, J = 17.1, 10.4, 6.5, C₂-H), 5.21 (1H, dt, J = 17.1, 1.5 Hz, C₁-H-trans), 5.14 (1H, dt, J = 10.4, 1.3, C₁-H-cis), 3.86-3.83 (1H, m, CH), 1.75-1.68 (1H, m, CH), 1.73 (1H, hidden br. s, OH), 0.93 (3H, d, J = 6.8, CH3), 0.90 (3H, d, J = 6.8, CH3)

Solvent peaks of THF can be seen at δ 3.76 (m, CH2O), 1.85 (m, CH2)

I must apologize that the integrals didn't make it in the .pdf I made. But they are accurate to the denotation I made.
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Now I know that the olefin-H cannot be dt, since they split between the geminal H, vicinal H and might go beyond to the CH connecting to the -OH. But I see a dt on the NMR. Should I just call it a m and disregard of what the NMR says?

[movies]

Ah, the familiar allyl group.

What you actually have is a ddd.  The coupling for the geminal H and the allylic H are just both about the same.  It is very common to see this in an allyl-containing compound.  You are just lucky that you don't have two diastereotopic Hs at the allylic position that would make it a dddd!

Anyway, there are two legitimate ways to report this.  The one I prefer is "ddd, J = 17.1, 1.5, 1.5 Hz."  You can also call it an "apparent dt" and just show two coupling values.  Calling any clean splitting an "m" is a little lazy, in my opinion.  At least show that you made some effort to deconvolute it.

Why are you taking crude NMRs in d-THF??  That stuff is expensive!

[Telamond]

Well, it's not d-THF. It's plain THF. The d-CDCl₃ peak can be seen to the right of the spectrum.

I'm a wuss when I'm using the rotary evaporator.  
I'm always afraid that my product will decompose or rearrange or evaporate if I pump it too long.

Anyways! Thanks for your *delete me*

[Dan]

Anyway, there are two legitimate ways to report this.  The one I prefer is "ddd, J = 17.1, 1.5, 1.5 Hz."  You can also call it an "apparent dt" and just show two coupling values.  Calling any clean splitting an "m" is a little lazy, in my opinion.  At least show that you made some effort to deconvolute it.

Just out of interest, what would you say about this method of reporting it:

(dt, J_gem 17.1, J_1,2 = J_1,3 1.5)