PINACOLONE
3,3-dimethyl-2-butanone (C6H12O)
NMR 1H APPROXIMATION OF
3,3-dimethyl-2-butanone
C-1
Carbon-3 is bound to 3 adjacent methyl groups. As a result, the protons attached to each
adjacent carbon are identical. This results in a singlet; protons on adjacent carbons do not couple:
There is no adjacent proton on carbon 3, so there is only a single peak. The absorbency is approximately
1.1 ppm which is consistent with the general range methyl groups would fall when bound to a carbon
lacking any deshielding atoms – 0.9-1.5 ppm.
Carbon-1 had an absorbency of approximately 2.2 ppm. Protons adjacent to ketones tend to
absorb at 2-2.5 ppm. This proton also yielded a single peak because the only atom adjacent to C-1 is C-2
which lacks any protons.