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Topic: What is the structure of unknown compound from my 1H NMR , 13C nmr and dept 135  (Read 3913 times)

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Offline fernnieee

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I need help to determine the structure of unknown compound from my 1H NMR , 13C nmr and dept 135 spectrum?
I am a student and in my organic chemistry class we each had an unknown chemical from natural product. It dissolve in water.
On the bottom of the H NMR sheet it says:
Label --- Assigned Value --- Freq. Limits (ppm)
1 --- 3.16 --- 1.8 ppm (multipret)
2 --- 1.00 --- 2.1 ppm (doublet)
3 --- 2.19 --- 3.2 ppm (multipret)
4 --- 0.90 --- 3.85 ppm (doublet-doublet)
5 --- 0.99 --- 4.2 ppm (singlet)
6 --- 0.12 --- 9.9 ppm
On the bottom of the C NMR and dept 135 sheet it says:
Label --- Freq. Limits (ppm)
1--28.04 (positive)
2--32.87 (positive)
3--38.69 (positive)
4--54.09 (negative)
5--61.9 (negative)
6-174.27
From this nmr,I think it showed 5 carbon and one carbon attached oxygen

In dept 135, positive peak means it is CH or CH3 and negative means it is CH2. It concluded that it has 3 groups CH or CH3. and 2 groups of CH2

From nmr, It hasn't aromatic ring. it has peak in alkyl chain. peaks look like in sugar region

I need to determine the structure AND the name of my unknown chemical from the H NMR spectrum, but it is a little difficult for me to understand how to do so. Thanks you for any help
« Last Edit: March 24, 2015, 09:30:09 AM by fernnieee »

Offline Dan

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You must show you have attempted the question, this is a Forum Rule.

Presumably you know something about splitting patterns in 1H NMR?
Have you been given (or can you determine) the coupling constants?
Do you know what positive/negative peaks mean in 13C DEPT?

Bear in mind that this looks like a ~10:1 mixture of two compounds.
My research: Google Scholar and Researchgate

Offline fernnieee

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From this nmr,I think it showed 5 carbon and one carbon attached oxygen

In dept 135, positive peak means it is CH or CH3 and negative means it is CH2. It concluded that it has 3 groups CH or CH3. and 2 groups of CH2

From nmr, It hasn't aromatic ring. it has peak in alkyl chain. peaks look like in sugar region

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