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Lactulose 1H NMR identification

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Machuu:
Hi,
I have a problem with interpretation of Lactulose 1H NMR spectrum. Lactulose has 14 protons (excluding OH groups). And my question is what is the location of signals from these protons in the spectrum? The doctoral student said that the signals have location about 3,80 - 5,80 ppm, but I can't find any publication to prove it. I need a signal location from a known number of protons to make integration the rest of the molecule.


Thanks for help.

Mitch:
It looks like you have more than lactulose in that spectrum. I suggest you use a prediction software program for sugar NMRs, or you will be struggling for a while to decide which proton gets shifted in which direction.

This online prediction program gave the simulated NMR attached below:
https://www.nmrdb.org/new_predictor/index.shtml?v=v2.103.0

Machuu:
To put it precisely it's lactulose modified by esterification. That kind of molecule was synthesized for the first time, so i must find singals from known protons e.g those coming directly from lactulose (14)

Mitch:
Did you try entering your molecule in the simulator? It will show you which protons generate which signals.

Machuu:
Yes I did, the signals have similar range. Thanks for help.
But now I have another question.

The solvent was CDCl3 so the signals must come from another compound. Do you have any suggestions?

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