13 C NMR EXAMPLES....... cyclohexanon-2-ene

C6H8O

 cyclohexanon-2-ene

Interpret :

d (ppm)	Multiplicity (n + 1)	Indicating
198	singlet
145	doublet	> CH = CH <
129	doublet
47	triplet
41	triplet
30	triplet	- CH2-

The peak is a singlet, indicating that it corresponds to a carbon bearing no hydrogens. The chemical shift (d 198) suggests that the carbon is a carbonyl, most likely an aldehyde or ketone.

The peak is a doublet, indicating that it corresponds to a CH. The chemical shift (d 145) is in the "alkene" region.

> CH = CH <

The peak is a doublet, indicating that it corresponds to a CH. The chemical shift (d 129) is in the "alkene" region.

> CH = CH <

The peak is a triplet, indicating that it corresponds to a CH₂ group. The chemical shift (d 47) suggests that the CH₂ is adjacent to something mildly electronegative (i.e., a carbonyl or an alkene p-system).

The peak is a triplet, indicating that it corresponds to a CH₂ group. The chemical shift (d 41) suggests that the CH₂ is adjacent to something mildly electronegative (i.e., a carbonyl or an alkene p-system).

The peak is a triplet, indicating that it corresponds to a CH₂ group. The chemical shift (d 30) is in the "simple" range, suggesting a simple internal CH₂.

- CH₂-

Molecular formula and index of hydrogen deficiency

C₆H₈O

The index of hydrogen deficiency is 3 (3 double bonds or rings)

Structural formula