Question

The carbon atoms of a phenol molecule is labeled as shown in the
figure. The 13C chemical shift values (in ppm) are:
C1: 155.02; C2 and C6: 115.48; C3 and C5: 129.79; C4: 121.09. In
comparison, benzene exhibits a single 13C line at 128.36 ppm.
Please explain why the chemical shift value of C1 in phenol is so much
higher than 128.36 and why the chemical shift values of C2, C4, C6 are
obviously lower than 128.36. Note that you will need to draw resonance
forms. (6’)

Answer 1