7th solutions manual for spectrometric identification of organic compounds

Answers for Student Exercises 1.1 to 1.5

1

a
3-ethyloctane
C10H22

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

IHD
0

Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
22
10
12.00000
14.0031
0
15.9949

0
31.9721
0
78.9183
0
Exact Mass

Total Mass
22.17226
120.00000
0.00000
0.00000
0.00000
0.00000
142.17226

- (C2H5 )
Rule 3

- (C5H11 )
Rule 3
H

- (CH2=CH2)
Rule 9

b

3-butylcyclohex-1-ene
C10H18

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

IHD
2

Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

or

- (C4H9 )
Rule 5 and 6

- (CH2=CH2)
Rule 6

- (C3H7 )
Rule 3

# of Atoms
Mass
1.00783
18
10

12.00000
14.0031
0
15.9949
0
31.9721
0
78.9183
0
Exact Mass

Total Mass
18.14094
120.00000
0.00000
0.00000
0.00000
0.00000
138.14094


Answers for Student Exercises 1.1 to 1.5

2
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur

Bromine

O
c

2-methyl-1-phenylhexan-1-one
C13H18O

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

IHD
5

# of Atoms
Mass
1.00783
18
13
12.00000
14.0031
0
15.9949
1
31.9721
0
78.9183
0
Exact Mass

O

O

Total Mass
18.14094
156.00000
0.00000
15.99490
0.00000
0.00000
190.13584

O

- (C6H13 )
Rule 8
O

O

- (C6H5 )
Rule 8

O

H

O

- (C4H8)

OH
H

Rule 9
O
- (CO)
Rule 8+9
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

d
(E)-undec-3-ene
C11H22

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

IHD
1

or

- (CH3)

Rule 5
- (C6H13)
Rule 5
H

- (C7H14)
Rule 9

# of Atoms
Mass
1.00783
22
11
12.00000
14.0031
0
15.9949
0
31.9721
0
78.9183
0
Exact Mass

Total Mass
22.17226
132.00000
0.00000
0.00000
0.00000

0.00000
154.17226


Answers for Student Exercises 1.1 to 1.5
e

1-(hexan-2-yl)benzene
C12H18

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

IHD
4

3
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
18
12

12.00000
14.0031
0
15.9949
0
31.9721
0
78.9183
0
Exact Mass

Total Mass
18.14094
144.00000
0.00000
0.00000
0.00000
0.00000
162.14094

- (CH3 )
Rule 7

- (C4H9 )
Rule 7
- (C4H8 )

H

H

Rule 9
H
f

OH
heptan-2-ol
C7H16O

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

OH

OH

H
OH

H
OH

IHD
0

Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen

Sulfur
Bromine

# of Atoms
Mass
1.00783
16
7
12.00000
14.0031
0
15.9949
1
31.9721
0
78.9183
0
Exact Mass

Total Mass
16.12528
84.00000
0.00000
15.99490
0.00000
0.00000
116.12018

- (C5H11 )
Rule 8

OH

- (CH3 )
Rule 8

OH

- (H )
Rule 8
- (H2O)
Rule 9

OH


Answers for Student Exercises 1.1 to 1.5

g

COOH
3,5,7-trimethyloctanoic acid
C11H22O2

CnHmXxNyOz

IHD
1

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

4
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
22
11
12.00000
14.0031
0
15.9949
2
31.9721
0
78.9183
0
Exact Mass

Total Mass
22.17226
132.00000
0.00000

31.98980
0.00000
0.00000
186.16206

O
C
O

- (OH )
OH

Rule 8

O
C

O
OH

H

O

O

- (C10H21 )

C

Rule 8

O

- (C9H18)
Rule 9

HO
h

OH
hexan-1-ol
C6H14O

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

IHD
0

Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

O
C

OH
H

OH

OH

HO

HO

# of Atoms
Mass
1.00783
14
6
12.00000
14.0031
0
15.9949
1
31.9721
0
78.9183
0
Exact Mass

Total Mass
14.10962

72.00000
0.00000
15.99490
0.00000
0.00000
102.10452

H
H

O

- (CH2=CH2 ) - (H2O)
Rule 9

OH

- (C5H11 )
Rule 8

H 2C

OH

- (H )
OH

Rule 8

OH

Answers for Student Exercises 1.1 to 1.5

i

OH
2-methylheptan-2-ol
C8H18O
CnHmXxNyOz

IHD
0

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

5
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
18
8

12.00000
14.0031
0
15.9949
1
31.9721
0
78.9183
0
Exact Mass

Total Mass
18.14094
96.00000
0.00000
15.99490
0.00000
0.00000
130.13584

- (C5H11 )

OH

OH

Rule 8
- (CH3 )

OH

OH

Rule 8

H
H

O

- (H2O)

- (CH2=C(CH3)2)

Rule 8

Rule 8

j

S
butyl(propyl)sulfane
C7H16S

CnHmXxNyOz
Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

S

IHD

0

Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
16
7
12.00000
14.0031
0
15.9949
0
31.9721
1
78.9183
0
Exact Mass

- (C3H7 )
Rule 8

- (CH2=CH2)

S

Rule 9

H

S

Total Mass
16.12528
84.00000
0.00000
0.00000
31.97210
0.00000
132.09738

- (C2H5 )
Rule 8

S

SH

S


Answers for Student Exercises 1.1 to 1.5
k

OH
(2-hexylphenyl)methanol
C13H20O
CnHmXxNyOz

IHD
4

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

OH

6
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
20
13
12.00000
14.0031
0

15.9949
1
31.9721
0
78.9183
0
Exact Mass

OH

or

- (C5H11 )

OH

OH

Rule 7

CH2
CH2

- (OH )

OH

Total Mass
20.15660
156.00000

0.00000
15.99490
0.00000
0.00000
192.15150

Rule 7
OH

- (H2O)

H

Rule 9

O
l

NO2
(4-nitrophenyl)(phenyl)methanone
C13H9NO3

CnHmXxNyOz

IHD
10

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

Atom Type

Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
9
13
12.00000
14.0031
1
15.9949
3
31.9721
0
78.9183
0
Exact Mass

Total Mass
9.07047
156.00000
14.00310
47.98470
0.00000
0.00000

227.05827

O

O
- (C6H4NO2 )
NO2
O

Rule 7&8
- (CO)
Rule 8&9
O

O
- (C6H5 )
NO2

Rule 7&8

NO2


Answers for Student Exercises 1.1 to 1.5

m

O

3-(ethoxymethyl)heptane

C10H22O

CnHmXxNyOz

IHD
0

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

7
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

# of Atoms
Mass
1.00783
22
10
12.00000
14.0031
0
15.9949
1
31.9721
0

78.9183
0
Exact Mass

- (CH3 )

O

O
CH2

Rule 8

- (C7H15 )

O

Total Mass
22.17226
120.00000
0.00000
15.99490
0.00000
0.00000
158.16716

O

Rule 8

- (C4H9)

O

O

Rule 3

O
n

H
Br
2-bromodecanal
C10H19BrO

CnHmXxNyOz

IHD
1

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

O

Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen

Sulfur
Bromine

# of Atoms
Mass
1.00783
19
10
12.00000
14.0031
0
15.9949
1
31.9721
0
78.9183
1
Exact Mass

Total Mass
19.14877
120.00000
0.00000
15.99490
0.00000
78.91830
234.06197

O

- (H )
H

Br

Rule 8

Br

O
- (CO )
Rule 9

Br

Br
H

H O
H
Br

- (C8H16)
Rule 9

O
H

H
Br

Answers for Student Exercises 1.1 to 1.5
o

O
O
cyclohexyl acetate
C8H14O2
CnHmXxNyOz

Index = (n) - (m/2) - (x/2) + (y/2) + 1 =

O

O

IHD
2

8
Atom Type
Hydrogen
Carbon
Nitrogen
Oxygen
Sulfur
Bromine

- (C6H11O )

# of Atoms
Mass
1.00783
14
8
12.00000
14.0031
0
15.9949
2
31.9721
0
78.9183
0
Exact Mass

Total Mass
14.10962
96.00000
0.00000
31.98980
0.00000
0.00000
142.09942

O

Rule 8

O

O

- (CH3 )

O

O

Rule 8

O
H

O

- (CH2=C=O)
Rule 9

O

H


Answers for Student Exercises 1.6 to 1.11
A

O

9

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

71

114

99 / C6H11O

15 / CH3

86 / C5H10

28 / C2H4

71 / C4H7O

43 / C3H7

58 / C3H5O

56 / C4H8

43 / C3H7

71 / C4H7O

4-Heptanone
C7H14O
Exact Mass: 114.1045
IHD = 1, match with (k)

B

OH

4-Bromotoluene
C7H7Br
Exact Mass: 169.9731
IHD = 4, match with (v)

D

Fragement Ion

Fragment Loss

59

116 by CI

115 / C7H15O

1/H

98 / C7H14

18 / H2O

87 / C5H11O

29 / C2H5

69 / C5H9

18 / H2O, 29 / C2H5

59 / C3H7O

57 / C4H9

45 / C2H5O

71 / C5H11

43 / C3H7

73 / C4H9O

41 / C4H5

18 / H2O, 57 / C4H9

R

Rearrangment
R
R

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

91

170

91 / C7H7

79 / Br

Rearrangment
Tropylium
Ion

75 / C6H3

80 / HBr, 16 / CH4

R

65 / C5H5

79 / Br, 26 / C2H2

R

50 / C4H2

120 / C7H5Br

39 / C3H2

131 / C4H5Br

Br

2-Bromopentane
C5H11Br
Exact Mass: 150.0044
IHD = 0, match with (r)

R

Molecular
Ion

C7H16O
Exact Mass: 116.1201
IHD = 0, match with (m)

Br

R

Base Peak

3-Heptanol

C

Rearrangment

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

71

150

121 / C3H6Br

29 / C2H5

107 / C2H4Br

43 / C3H7

71 / C5H11

79 / Br

55 / C4H7

80 / HBr, 16 / CH4

43 / C3H7

C2H4Br

Rearrangment

R


Answers for Student Exercises 1.6 to 1.11
O

E

10

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

43

100

85 / C5H9O

15 / CH3

71 / C4H7O

29 / C2H5

58 / C4H10

42 / C2H2O

57 / C3H5O

43 / C3H7

43 / C3H7

57 / C3H5O

2-Hexanone
C6H12O
Exact Mass: 100.0888
IHD = 1, match with (h)

O

F

OH
Propionic Acid

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

74

74

73 / C3H5O2

1/H

57 / C3H5O

17 / OH

56 / C3H4O

18 / H2O

45 / CHO2

29 / C2H5

C3H6O2
Exact Mass: 74.0368
IHD = 1, match with(c)

G

H2N

OH

prop-2-yn-1-ol
C3H4O
Exact Mass: 56.0264
IHD = 2, match with (a)

R

Rearrangment

R

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

Rearrangment

73

73

56 / C4H8

17 / NH3

R

55 / C4H7

18 / NH4

R

44 / C2H6N

29 / C2H5

43 / C3H7

30 / CH4N

butan-1-amine
C4H11N
Exact Mass: 73.0896
IHD = 0, match with (b)

H

Rearrangment

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

55

56 by CI

55 / C3H3O

1/H

39 / C3H3

17 / OH

38 / C3H2

18 / H2O

Rearrangment


Answers for Student Exercises 1.6 to 1.11

I

O
N

+

O-

11

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

43

89 by CI

90 / C3H8NO2

Addition of H

72 / C3H6NO

17 / OH

43 / C3H7

46 / NO2

42 / C3H6

47 / HNO2

R

Rearrangment

1-Nitropropane
C3H7NO2
Exact Mass: 89.0477
IHD = 1, match with (d)

J

OH
O

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

94

138

107 / C7H7O

31 / CH3O

94 / C6H5O

44 / C2H4O

77 / C6H5

61 / C2H5O2

66 / C5H6

72 C3H5O2

51 / C4H3

87 / C4H7O2

39 / C3H2

99 / C5H8O2

2-Phenoxylethanol
C8H10O2
Exact Mass: 138.0681
IHD = 4, match with (q)

K
O
Phenetole

O
O
Methyl Butyrate

C5H10O2
Exact Mass: 102.0681
IHD = 1, match with (i)

R

R
R

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

Rearrangment

94

122

94 / C6H5O

28 / C2H4

R

77 / C6H5

45 / C2H5O

66 / C5H6

56 / C3H4O

51 / C4H3

71 / C4H7O

39 / C3H2

83 / C5H8O

C8H10O
Exact Mass: 122.0732
IHD = 4, match with (o)

L

Rearrangment

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

43

102

87 / C4H7O2

15 / CH3

74 / C3H5O2

28 / C2H4

71 / C4H7O

31 / CH3O

59 / C2H3O2

43 / C3H7

43 / C3H7

59 / C2H3O2

Rearrangment
R


Answers for Student Exercises 1.6 to 1.11
O

M
HN

12

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

Rearrangment

113

113

85 / C5H11N

28 / CO

R

84 / C5H10N

29 / CHO

56 / C4H8

57 / C2H3NO

55 / C4H7

58 / C2H4NO

42 / C3H6

71 / C3H5NO

R

Rearrangment

Caprolactam
C6H11NO
Exact Mass: 113.0841
IHD = 2, match with (j)

N

N
N
2-methylpyrazine

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

94

94

67 / C4H5N

27 / CHN

53 / C3H3N

41 / C2H3N

42 / C2H4N

52 / C3H2N

41 / C2H3N

53 / C3H3N

40 / C2H2N

54 / C3H4N

C5H6N2
Exact Mass: 94.0531
IHD =4, match with (e)

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

152

152

135 / C8H7O2

17 / OH

122 / C7H6O2

30 / CH2O

R

107 / C7H7O

45 / CHO2

R

Methyl salicylate

105 / C7H5O

17 / OH, 30 / CH2O

R

C8H8O3
Exact Mass: 152.0473
IHD = 5, match with (s)

92 / C6H4O

R

77 / C6H5

60 / C2H4O2

17 / OH, 58 /
C2H2O2

63 / C5H3

89 / C3H5O3

39 / C3H2

113 / C5H6O3

Fragement Ion
141 /
C6H4ClNO

Fragment Loss

127 / C6H4O

30 / NO

111 / C6H4Cl

46 / NO2

99 / C5H4Cl

58 / CNO2

75 / C6H3

46 / NO2, 36 / HCl

50 / C4H2

107 / C2H2ClNO2

O

HO
O
O

P
O
N+
-

Cl

O

1-Chloro-4-Nitrobenzene
C6H4ClNO2
Exact Mass: 156.9931
IHD = 5, match with (t)

Base Peak

Molecular

Ion

75 or 157

157

Rearrangment

Rearrangment

16 / O
R

R


Answers for Student Exercises 1.6 to 1.11
Q

O

HO

Br

13

Base Peak

Molecular

Ion

Fragement Ion

Fragment Loss

60

208 by CI

191 / C7H12OBr

17 / OH

149 / C5H10Br

59 / C2H3O2

129 / C7H13O2

79 /Br

111 / C7H11O

79 /Br, 18 / H2O

R

83 / C6H11

125 / CH2BrO2

R

60 / C2H4O2

147 / C5H9Br

R

Rearrangment

7-Bromo Heptanoic Acid
C7H13BrO2
Exact Mass: 208.0099
IHD = 1, match with (w)

R
HO
5-Hexyn-1-ol
C6H10O
Exact Mass: 98.0732
IHD = 2, mathc with (g)

O

S

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

70

98

97 / C6H9O

1/H

83 / C5H7O

15 / CH3

79 / C6H7

19 / H3O

70 / C4H6O

28 / C2H4

Base Peak

Molecular

Ion

Fragement Ion

Fragment Loss

43

126

111 / C7H11O

15 / CH3

108 / C8H12

18 / H2O

R

93 / C7H9

33 / CH5O

R

83 / C6H11

43 / C2H3O

69 / C5H9

57 / C3H5O

58 / C3H6O

68 / C5H8

55 / C4H7

71 C4H7O

43 / C2H3O

83 / C6H11

6-Methyl-5-hepten-2-one
C8H14O
Exact Mass: 126.1045
IHD = 2, match with (p)

T O
HO
Hexanoic acid
C6H12O2
Exact Mass: 116.0837
IHD = 1, match with (l)

Rearrangment

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

60

116 by CI

87 / C4H7O2

29 / C2H5

73 / C3H5O2

43 / C3H7

60 / C2H4O2

56 / C4H8

45 / CHO2

71 / C5H11

Rearrangment

R

Rearrangment

R


Answers for Student Exercises 1.6 to 1.11
U
HO

Cl

14

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

Rearrangment

162

162

126 / C6H3OCl

36 / HCl

R

98 / C5H3Cl

64 / CHOCl

R

63 / C5H3

99 / CHOCl2

Cl
2,6-Dichlorophenol
C6H4Cl2O
Exact Mass: 161.9639
IHD = 4, match with (u)

V HO

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

122

122

121/C8H9O

1/H

107/C7H7O

15 / CH3

91 / C7H7

31 / CH3O

77 / C6H5

45 / C2H5O

65 / C5H5

57 / C3H5O

2,6-Dimethylphenol
C8H10O

Exact Mass: 122.0732
IHD = 4, match with (n)

W

O

2-Cyclohexen-1-one
C6H8O
Exact Mass: 96.0575
IHD = 3, match with (f)

Rearrangment

Base Peak

Molecular
Ion

Fragement Ion

Fragment Loss

Rearrangment

68

96

68 / C4H4O

28 / C2H4

R

55 / C3H3O

41 / C3H5

53 / C4H5

43 / C2H3O

42 / C2H2O

54 / C4H6

R


Answers for Student Exercise 2.1 – 2.9

1

2.1. Since the indicated carbon of phenylacetonitrile is sp3 hybridized, it is reasonable for this compound to
show C−H stretching at less than 3000 cm-1 (2960-2940 cm-1). Where as benzonitrile has only aromatic
C−H stretching which is typically between 3100 - 3000 cm-1 (page 87).

CH2

N

C

C N

phenylacetonitrile

benzonitrile

2.2.
O
N

H 2N
b. isobutylamine

a. benzonitrile

HO

O

S
O

O

c. diphenyl sulfone

d. dioxane

O
g. biphenyl

f. formic acid

N+

O

O-

e. 1-nitropropane

HO

H 2N

O

O

h. benzoic acid

i. benzamide

2.3.

1,3-Cyclohexadiene

Diphenylacetylene

Spectrum B

Spectrum A

1-Octene
Spectrum D

2-Pentene
Spectrum C

2.4.
O
O

O

NH2
O

H 2N

HO

O
O-

C11H23

Na+

Butyl acetate

Butyramide

Isobutylamine

Lauric acid

Sodium propionate

Spectrum E

Spectrum H

Spectrum I

Spectrum F

Spectrum G

2.5.
HO

O
O
Allyl phenyl ether
Spectrum L

HO
H

Benzaldehyde

Spectrum M

O

o-Cresol
Spectrum K

m-Toluic acid
Spectrum J


Answers for Student Exercise 2.1 – 2.9

2

2.6.
HO

N
H 2N

N
H 2N

NH2 Cl

N

Aniline

Azobenzene

Spectrum Q

Spectrum O

Benzophenone oxime
Spectrum P

2.7.

Methyl isothiocyanate CH3−N=C=S

2.8.

This diketone exists primarily (~ 90%) in enol form (in CCl4)
O

O

O

H

Benzylamine
Spectrum N

Dimethylamine
hydrochloride
Spectrum R

O

enol

Enols such as this display broad, shallow O−H stretching bands (here from 3400-2500 cm-1). The
strong band at ~1600 cm-1 is the enolic coupled C=C−OH band. (See pages 80, 94, and 98)


Answers for Student Exercise 2.1 – 2.9

3

2.9.
O

OH

4-Heptanone

3-Heptanol

4-Bromotoluene

A

B

C

Br

Br

2-Bromopentane

D

O

O

OH

H 2N

OH
2-Hexanone

Propionic Acid

Butylamine

Propargyl alcohol

E

F

G

H

OH

O
N+

O-

O

1-Nitropropane

O

O

O
2-Phenoxylethanol

Phenetole

J

K

I

MethylHButyrate

L

HO

O

O

N

HN
N

O
N+

O

-

Cl

O

Caprolactam

2-methylpyrazine

Methyl salicylate

1-Chloro-4-Nitrobenzene

M

N

O

P

O

O

HO

Br

HO

7-Bromo Heptanoic Acid

5-Hexyn-1-ol

6-Methyl-5-hepten-2-one

R

S

Q

HO

Cl

O

HO

O
Cl

HO
Hexanoic acid

T

2,6-Dichlorophenol

U

2,6-Dimethylphenol

2-Cyclohexen-1-one

V

W


Answers for Student Exercise 3.1 to 3.3

1
4

3

2

1

Br

(a) 1-bromobutane

3.1(a) 1,2,3,4 are a spin system. Pople notation is A3M2S2X2. 1,2, and 3 are enantiotopic.
3.2 (a)
Spin
1
2
3
4

Appr. δ
δ 3.40
δ 1.85
δ 1.20
δ 0.85

Table
Appendix A, Chart A.1
Appendix A, Chart A.2
Appendix A, Chart A.1
Appendix A, Chart A.1

Coupled with
2
1,3
3, 4
3

Multiplet (n+1)
Triplet
Quintet
Sextet
Triplet

Integration
2
2
2
3

3.3 (a)

1

2

3

4


Answers for Student Exercise 3.1 to 3.3

2
5

6

4

1
3

2

7

O
O 8

9

(b) (cyclohex-2-enyl)methyl acetate

3.1 (b) 1,2,3,4,5,6,7 are one spin system, and 9 is the second. 4,4’ ; 5,5’ ; 6,6’and 7,7’ are
diastereotopic.
3.2 (b)
Spin
Table or Calculation
Coupled with Multiplet (n+1)
Integration
Appr. δ
1
Appendix A, Chart A.2
6,2,7
Sextet*
1
δ 2.80
2
Appendix D, Chart D2
3,1
Triplet*
1
δ 5.59
3
Appendix D, Chart D2
Quartet*
1
δ 5.59

Appendix
D,
Chart
D2
Quartet**
2
δ 1.96
4
Appendix D, Chart D2
4,6
Quartet**
2
δ 1.65
5
Appendix A, Chart A.2
1,5
Triplet**
2
δ 1.80
6
Appendix A, Chart A.2
1
Doublet**
2
δ 4.05
7
Appendix A, Chart A.1
none
Singlet
3

δ 2.10
9
* Coupling constants may not be the same, but make the assumption that they are.
**These are diastereotopic, and are coupled to diastereotopic protons, they would not be first order.
We will assume they are first order for the drawn spectrum.

3.3 (b)

2

2 and 3

7

1

9

4

6

5


Answers for Student Exercise 3.1 to 3.3

3
2
3

O
1

7
6

4
5

9
8

OH

10

(c) 1-(cyclohexa-1,5-dienyl)-3hydroxy-2-methylpropan-1-one

3.1 (c) 2,3,4,5,6 are a spin system, and 8,9,10 another spin system. 3,3’ ; 4,4’ ; 9,9’ are diastereotopic.
3.2 (c)
Spin
Table or Calculation
Coupled with Multiplet (n+1)
Integration
Appr. δ
2
Appendix
D,
Chart

D.1
3
Triplet
1
δ 6.68
3
Appendix A, Chart A1
2,4
Quartet***
2
δ 2.05
4
Appendix A, Chart A1
3,5
Quartet***
2
δ 2.05
Appendix D, Chart D1
4,6
Quartet*
1
5
δ 5.68
Appendix D, Chart D1
5
Doublet
1
δ 6.22
6
Appendix

A,
Chart
A.1
9,10
Sextet
1
δ 2.65
8
Appendix A, Chart A.1
8
Doublet**
2
δ 3.20
9
Appendix A, Chart A.2
8
Doublet
3
δ 1.05
10
1
δ 0.5-4.0 Appendix E
ΟΗ
* Coupling constants may not be the same, but make the assumption that they are.
** These are diastereotopic, and are coupled to diastereotopic protons; they would not be first order.
We will assume they are first order for the drawn spectrum.

3.3 (c)

2

6

5

9

8

3,4

OH 10


Answers for Student Exercise 3.1 to 3.3

5

4

4

3 2 1
(d) pent-1-yne

H

3.1 (d) 5,4,3 are a spin system and 1 is second. 5,4,3 is Pople notation is A3M2X2; may have long rang
coupling. 3+4 are enantiotopic.
3.2 (d)

Appr. δ
δ 0.85
δ 1.50
δ 2.20
δ 1.80

Spin
5
4
3
1

Table or Calculation
Appendix A, Chart A.2
Appendix A, Chart A2
Appendix A, Chart A1
Appendix D, Chart D3

Coupled with Multiplet (n+1)
4
Triplet
3,5
Sextet
4
Triplet
none
Singlet

3.3 (d)

3

1

4

5

Integration
3
2
2
1


Answers for Student Exercise 3.1 to 3.3

5
O
1

5
6
4
(e) hex-3-en-2-one
2

3

3.1 (e) 3,4,5,6 are a spin system, and 1 is another spin system. Pople notation is A3G2MX. 5 is

enantiotopic.
3.2 (e)
Appr. δ
δ 1.86
δ 6.09
δ 6.82
δ 2.05
δ 1.00

Spin
1
3
4
5
6

Table or Calculation
Appendix D, Chart D.2
Appendix D, Chart D.1
Appendix D, Chart D.1
Appendix A, Chart A1
Appendix A, Chart A2

Coupled with Multiplet (n+1)
None
Singlet
4
Doublet
3, 5
Quartet*

4, 6
Quintet*
5
Triplet

Integration
3
1
1
2
3

* Coupling constants may not be the same, but make the assumption that they are.
3.3 (e)

4

3

5

1

6


Answers for Student Exercise 3.1 to 3.3

6

1

O 2

4
3

5

(f) 1-methoxybut-1-ene

3.1 (f) 3,4,5,6 are a spin system, and 1 is another spin system. Pople notation is A3G2MX. 4 is
enantiotopic.
3.2 (f)
Appr. δ
δ 3.20
δ 6.14
δ 4.63
δ 2.05
δ 1.00

Spin
1
2
3
4
5

Table or Calculation
Appendix A, Chart A.1

Appendix D, Chart D.1
Appendix D, Chart D.1
Appendix A, Chart A1
Appendix A, Chart A2

Coupled with Multiplet (n+1)
None
Singlet
3
Doublet
2, 4
Quartet*
3, 5
Quintet*
4
Triplet

Integration
3
1
1
2
3

* Coupling constants may not be the same, but make the assumption that they are.
3.3 (f)

2

3

1

4

5


Answers for Student Exercise 3.1 to 3.3

7

1

O
N 2 O 3
H

4

5

(g) propyl methylcarbamate

3.1 (g) 3,4,5 are a spin system, and 1 is another spin system. Pople notation is A3M2X2. 3 and 4 are
enantiotopic.
3.2 (g)
Spin
Table or Calculation
Appr. δ

1
Appendix A, Chart A.1
δ 2.95
3
Appendix D, Chart D.1
δ 4.10
4
Appendix A, Chart A.2
δ 1.60
5
Appendix A, Chart A1
δ 0.85
NH
δ 4.5-7.5 Appendix E
*See Section 3.6.2 for coupling between 1 and N-H.

Coupled with Multiplet (n+1)
None
Singlet
3
Triplet
2, 4
Sextet
3, 5
Triplet
*
Singlet

Integration
3

2
2
3
1

3.3 (g)

NH

3

1

4

5


Answers for Student Exercise 3.1 to 3.3

8

1

2 O 3 O
(h) diethoxymethane

3.1 (h) 1 and 2 are a spin system, and 3 is another spin system. Pople notation is A3X2. 2 are
enantiotopic.
3.2 (h)

Spin
1
2
3

Appr. δ
δ 1.20
δ 3.40
δ 4.95

Table or Calculation
Appendix A, Chart A.2
Appendix A, Chart A.1
Appendix B, Table B.1

Coupled with Multiplet (n+1)
2
Triplet
1
Quartet
none
Singlet

Integration
3
2
2

3.3 (h)

3

2

1