Chem 335 - Winter 2000
Organic Chemistry II
Dr. Carl C. Wamser

Chapter 13 Quiz

1. (6 points) Describe the expected 1-H and 13-C NMR spectra (fully coupled) for the compound below, using the format of the following example:

example - CH2=CH2 1-H NMR: singlet, 4H, 4.6-5.0 ppm; 13-C NMR: triplet, 100-150 ppm

1-H NMR:

a - singlet, 3H, 3.3 - 4.0 ppm
b - singlet, 3H, 0.8 - 2.0 ppm
c - triplet, 6H, 0.8 - 1.0 ppm
d - quartet, 4H, 1.2 - 2.0 ppm

13-C NMR:

a - quartet, 40 - 80 ppm
b - quartet, 0 - 40 ppm
c - quartet, 0 - 40 ppm
d - triplet, 15 - 55 ppm
e - singlet, 40 - 80 ppm

2. (4 points) Identify the unknown compound of formula C9H10Br2 that gives the proton NMR spectrum shown on the back of this page. Assign each of the signals to specific hydrogens. The 13-C NMR spectrum shows 7 (not 9) different absorptions.

Seven (not nine) CMR absorptions indicates 1,4 (para) substitution - otherwise all nine carbons would be distinct.