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Solutions for Structure and Synthesis of Alcohols
9 continued
C
O
N
OO
OH
A
N
O O
O
B
OH
Nitro at position 4 delocalizes negative charge.
Nitro group at position 4
Only when the nitro group is at one of the negative carbons will the nitro have a stabilizing effect (via 
resonance). Thus, 2-nitrophenol and 4-nitrophenol are substantially more acidic than phenol itself, but 3-
nitrophenol is only slightly more acidic than phenol (due to the inductive effect).
(a) Structure A is a phenol because the OH is bonded to a benzene ring. As a phenol, it will be acidic 
enough to react with sodium hydroxide to generate a phenoxide ion that will be fairly soluble in water. 
Structure B is a 2° benzylic alcohol, not a phenol, not acidic enough to react with NaOH.
(b) Both of these organic compounds will be soluble in an organic solvent like dichloromethane. Shaking 
this organic solution with aqueous sodium hydroxide will ionize the phenol A, making it more polar and 
water soluble; it will be extracted from the organic layer into the water layer, while the alcohol will remain 
in the organic solvent. Separating these immiscible solvents will separate the original compounds. The 
alcohol can be retrieved by evaporating the organic solvent. The phenol can be isolated by acidifying the 
basic aqueous solution and filtering if the phenol is a solid, or separating the layers if the phenol is a liquid.
10
Li F MgBr
Li
+ LiCl+ LiI
11 The Grignard reaction needs a solvent containing an ether functional group: (b), (f), (g), and (h) are 
possible solvents. Dimethyl ether, (b), is a gas at room temperature, however, so it would have to be 
liquefied at low temperature for it to be a useful solvent.
12 (a) CH3CH2MgBr (b) (c) (d)
MgI
MgCl
MgBr
C O
H
H
C
H
H
O
C O
H
H
H3O+
H3O+
H3O+
OH
CH2OH
CH2OH
13 Any of three halides—chloride, bromide, iodide, but not fluoride—can be used. Ether is the typical 
solvent for Grignard reactions. The new C—C bond is shown in bold.
(a)
(b)
(c)
+
+
+
Note: the alternative arrow symbolism 
could also be used, where the two steps 
are numbered around one arrow:
ether
ether
ether
1) ether
2) H3O+ OK
ether
H3O+
NO! My BAD!
This means that water is present with 
ether during the Grignard reaction!
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