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Chemistry 220/221
Chapter 13 Review
Draw the structures of the following compounds given the 1H-NMR data and the
molecular formula.
1. Formula: C3H8O2, singlet),  3.3 (singlet) in a 1:3 ratio.
CH3
O
CH2
O
CH3
2. Formula: C4H10O2,  3.3 (singlet),  3.4 (triplet) in a 3:2 ratio.
CH3
O
CH2
CH2
O
CH3
3. Formula: C5H12O2,  3.1 (singlet),  1.2 (singlet) in a 1:1 ratio.
CH3
H3C
O
C
O
CH3
CH3
4. Formula: C4H10O
a. Isomer 1H-NMR Data:
 1.13 (doublet, 6H),  3.30 (singlet, 3H),  3.65 (septet, 1H)
O
b. Isomer 1H-NMR Data:
 2.87 (broad singlet, 1H),  1.28 (singlet, 9H)
OH
c. Isomer 1H-NMR Data:
 0.95 (triplet, 3H),  1.52 (sextet, 2H),  3.30 (singlet, 3H),  3.40
(triplet, 2H),
CH3
CH2
CH2
O
CH3
d. Isomer 1H-NMR Data:
 0.90 (doublet, 6H),  1.78 (nonet, 1H),  2.45 (broad singlet,
1H),  3.30 (doublet, 2H),
CH3
CH
CH3
CH2
OH
2
e. Isomer 1H-NMR Data:
 1.20 (triplet),  3.45 (quartet), ratio 3:2.
CH3
CH2
O
CH2
CH3
f. Isomer 1H-NMR Data:
 0.92 (triplet, 3H),  1.18 (doublet, 3H),  1.45 (quintet, 2H), 
1.80 (broad singlet, 1H), 3.75 (sextet, 1H)
CH3
HO
C
H
CH2
CH3
5. Which hydrogens exhibit the more downfield signal relative to TMS in the proton
NMR? Explain your answer.
a. (CH3)2O or (CH3)3N
(CH3)2O Oxygen is more electronegative than N
b. (CH3)2S or (CH3)2S=O
(CH3)2S=O Attachment of oxygen increases the electron withdrawing
capacity of sulfur.
c.
O
H3C
C
O
CH3
OR
-OCH3 because it is next to oxygen
d.
CH3
CH2
CH2
OH
-CH2- is closer to the electronegative atom
6. How many chemical shifts would you expect for the following compounds?
(2 signals)
a. CH3CH2CH2CH3
b. CH3CHBrCH3
(2 signals)
c. HO-CH2CCl(CH3)2 (3 signals)
d. (CH3)2CH-CH2-CH3 (4 signals)
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e.
CH3
O
CH3
CH
CH3
CH2
C
CH3
CH3
(5 signals)
7. The following are isomeric esters derived from acetic acid, each with the formula
C5H10O2. The peaks of the spectrum have been labeled to indicate the degree of
splitting. With the first spectrum as an example. Use the integral curve traced on
the spectrum to calculate the number of hydrogens in each multiplet.
Spectrum (a) data:
1.7
0.202
X 10
2H
2.5
0.297
X 10
3H
1.7
0.202
X 10
2H
2.5
0.297
X 10
3H
Spectrum (b) data:
The second spectrum has a hydrogen pattern of 1:3:6. What are the structures of the
two esters?
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8. Following are the NMR spectra of three isomeric esters with the formula C7H14O2,
all derived from propanoic acid. Provide a structure for each of the spectra.