Predicting 1H NMR Spectra from Structures

An important exercise to carry out when learning about 1H nmr spectra is
predicting the 1H nmr spectrum of a molecule. There are several steps to
follow which make this much easier.
1. How many total signals are expected.
2. For each signal determine:
a. Chemical Shift
b. Splitting pattern
c. Relative intensity

The first set of problems below test your ability to predict the number of 1H
nmr signals expected for a molecule. Remember to look for symmetry.

1. Predict the number of signals that should be observed in the 1H nmr
spectrum for each of the following compounds.

O

CH3

H

H

H

H

H

C

H

H

CH3

H

H

O

H

O

N

H3C

H

H

CH3

CH

CH

H3C

Br

H3C

Br

H3C

CH3

Cl

Cl

2. In the molecules below: fill in the chemical shift, circle the appropriate
multiplicity expected (if more than 4(q) fill in the number) and give the
number of protons for each set of protons indicated in the molecules below,
than plot the spectrum.

CH2

O

CH2

CH3

H3C

H3C

C

H3C

H3C

O

CH3

H3C

CH

H3C

O

CH2

CH3

_____ ppm
sdtq

H

_____ ppm
sdtq

H

0

1

2

3

4

5

6

7

8

9

10

0

1

2

3

4

5

6

7

8

9

10

_____ ppm
sdtq

H

_____ ppm
sdtq

H

_____ ppm
sdtq

H

_____ ppm
sdtq

H

_____ ppm
sdtq

H

_____ ppm
sdtq

H

0

1

2

3

4

5

6

7

8

9

10

CH2

O

CH2

CH3

H3C

_____ ppm

s

d

t

q

H

_____ ppm

s

d

t

q

H

0

1

2

3

4

5

6

7

8

9

10

H3C

C

H3C

H3C

O

CH3

0

1

2

3

4

5

6

7

8

9

10

_____ ppm

s

d

t

q

H

_____ ppm

s

d

t

q

H

H3C

CH

H3C

O

CH2

CH3

_____ ppm

s

d

t

q

H

_____ ppm

s

d

t

q

H

_____ ppm

s

d

t

q

H

_____ ppm

s

d

t

q

H

0

1

2

3

4

5

6

7

8

9

10