Organic Chemistry II
	Professor Carl C. Wamser
Chem 335 - Winter 2005	Chapter 13 Quiz

1. (4 points) There are four possible isomers of C4H9Br (n-butyl, sec-butyl, tert-butyl, isobutyl).
Identify each one by the 1H NMR spectra described below.
Peaks marked with * are in the range 3-4 ppm, all other peaks fall between 1-2 ppm.

A - singlet, 9H (tert-butyl bromide)

B - doublet, 6H; multiplet, 1H; doublet*, 2H (isobutyl bromide)

C - triplet, 3H; multiplet, 2H, multiplet, 2H; triplet*, 2H (n-butyl bromide)

D - doublet, 3H; triplet, 3H; multiplet, 2H; multiplet*, 1H (sec-butyl bromide)

2. (6 points) Identify the unknown compound based on the data given below.
Indicate the specific structural information obtained from each item of data.
Identify every carbon and hydrogen in the NMR spectra (label them on your structure and on the spectra as a, b, etc).

a) Molecular formula: C4H7BrO2
calculate and interpret the index of hydrogen deficiency

IHD = 1 means one double bond or ring

b) Mass spectrum: M and M+2 peaks in equal intensity at (m/z) = 166, 168

The molecular weight is 166 and there is a Br atom present.

c) Infrared spectrum: no peaks in the range 3000-4000 cm-1, a strong peak at 1740 cm-1

There are no O-H bonds and no C-H bonds with sp2 or sp carbons.

d) 1H NMR spectrum:

2.8 ppm, triplet, 2H b

3.5 ppm, triplet, 2H a

3.7 ppm, singlet, 3H d

e) 13C NMR spectrum: four peaks at 27 (b), 38 (a), 52 (d), 171 (c) ppm