These can be solved using infrared and

1
These can be solved using infrared and an index
of hydrogen deficiency.
2
Problem 1
HINT Can be made from propyne when treated with
aqueous H2SO4 and HgSO4.
C3H6O
1421
1363
1715
3
Problem 2
HINT Can be made from ethyl iodide and a
good nucleophile in acetone (SN2).
C3H5N
2248
4
Problem 3
HINT Made by adding water to propene using 3M
H2SO4.
C3H8O
1162
3345
1130
970
5
Problem 4
HINT The solution to this one is in the
hydrogen deficiency index.
C5H10O
1162
994
3345
6
Problem 5
HINT The solution to this one is in the
hydrogen deficiency index.
C7H5N
2178
7
Problem 6
HINT The solution to this one is in the
hydrogen deficiency index.
C8H8O
1686
8
Problem 7
HINT This one stinks like rancid butter.
C4H8O2
1712
9
Problem 8
HINT There are two functional groups.
C3H4O
2121
10
Problem 9
HINT The two peaks at 2820 and 2738 are the key.
C7H6O
2738
2820
1703
11
Problem 10
C8H8O2
1112
1704
1279
12
PRACTICAL APPLICATION
This next problem is a little more difficult,
requiring both infrared and a knowledge of
reactions.
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Problem 11
As a project, Mary was given an unknown compound
A, and told to perform the reactions listed
below. At the end of each reaction step she was
told to submit the major product for
microanalysis, in order to obtain the molecular
formula, and to also determine its infrared
spectrum. The structure of each compound was to
be identified. Can you help her solve the
structures and pass this class? (Answers given 7
slides from this one!)
A
B
C
H2SO4/HgSO4
Ni / H2
C8H6
C8H8O
C8H10O
2 atm
H2O
TsCl
pyridine
NaCN
Spectra are on the pages that follow.
acetone
Ni / H2
C9H9N
C9H13N
2 atm
D
E
14
A
C8H6
2110
3310
15
C8H8O
B
1686
16
C8H10O
C
3353
17
C9H9N
D
2243
18
C9H13N
E
3374
3293
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Also check out Problems 74 and 75 at the end of
Chapter 12.
You should be able to solve these after we
have finished Chapter 11.