Chemistry Workshops

for Organic Chemistry

Workshop, Chapter 13
Spectroscopy / Structure Determination

1. Identify compounds of the given molecular formula that show only one 1H NMR signal:

C2H6O

C3H4

C2H4Br2

C4H6

C5H12

C5H10

2. Identify compounds of the given molecular formula that show only two 1H NMR signals:

C3H6Cl2

C3H6O2

C3H8O2

C2H5OCl

3. How many 1H NMR signals will each of the following compounds show?

a) (CH3)3CCH2CH3

b) CH3COCOOCH3

c) CH3COCH2COCH3

d) CH3COCH2CH2COCH3

e) CH3COCH2CH2COOCH3

f) CH3COCH2CHClCOCH3

4. Deduce the unknown structures from the data presented.

a) C4H8O
triplet (1.0 ppm, 3H)
singlet (2.1 ppm, 3H)
quartet (2.4 ppm, 2H)

b) C4H8O2
triplet (1.2 ppm, 3H)
singlet (2.1 ppm, 3H)
quartet (4.1 ppm, 2H)

c) C8H8O
singlet (2.4 ppm, 3H)
multiplet (7.5 ppm, 5H)

d) C2H5BrO
singlet (3.3 ppm, 3H)
singlet (4.9 ppm, 2H)

e) C4H9Br
doublet (1.1 ppm, 6H)
multiplet (1.9 ppm, 1H)
doublet (3.4 ppm, 2H)

f) C4H8O3
triplet (1.3 ppm, 3H)
quartet (3.7 ppm, 2H)
singlet (4.2 ppm, 2H)
singlet (11.0 ppm, 1H)

g) C3H7ClO
triplet (1.4 ppm, 3H)
quartet (3.8 ppm, 2H)
singlet (5.6 ppm, 2H)

h) C6H12O2
singlet (1.2 ppm, 6H)
singlet (2.1 ppm, 3H)
singlet (2.8 ppm, 2H)
singlet (3.7 ppm, 1H)