Calculating Percent Enol Content of 2-Acetylcyclohexanone Using H-NMR

[sweetlemontea]

hi
i'm trying to figure out the percent enol content of 2-acetylcyclohexanone but with little success. i have been given an H-nmr of 2-acetylcyclohexanone and one of the deuterated derivative.
i know that the proton from the -OH group of the enol form shows up at around 16ppm but the other peaks are a little more confusing.
i need a little help in assigning the peaks and finding the percent enol content.
thanks in advance

 

[chemisttree]

The deuterated version won't have the beta hydrogen or the hydroxyl hydrogen. That will help you identify those peaks since those are present in one spectrum and not the other. They should both be singlets with the hydroxyl one being somewhat broad... you might not even see it. 16 ppm doesn't sound like a hydroxyl proton, though.

Were you given the integrated intensities for the spectra?

 

[quicknote]

Hello, calculating the percent enol content of 2-acetylcyclohexanone can be a challenging task, but with the right approach, it can be done successfully. Firstly, it is important to understand the concept of enol content and how it relates to H-NMR spectroscopy. Enol content refers to the percentage of the enol form present in a molecule relative to the keto form. In H-NMR spectroscopy, the enol form typically shows up as a broad peak around 16ppm, as you have mentioned.

To accurately determine the percent enol content, you will need to integrate the peak corresponding to the enol form and compare it to the integration of the other peaks in the spectrum. The integration values represent the relative number of protons contributing to each peak. Based on the relative integration values, you can calculate the percent enol content using the following equation: percent enol content = (enol peak integration / total integration) x 100%.

In order to assign the peaks in the spectrum, you can use the deuterated derivative as a reference. The deuterated derivative will have the same peaks as the original molecule, but they will be shifted to a different location due to the deuterium isotope effect. By comparing the positions of the peaks in the deuterated derivative to those in the original spectrum, you can assign the peaks accurately.

I hope this helps in your analysis of the percent enol content of 2-acetylcyclohexanone. If you need further assistance, I would suggest consulting with a colleague or a mentor who has experience in this type of analysis. Good luck!