Chapter 13
Alcohols
Review of Concepts
Fill in the blanks below. To verify that your answers are correct, look in your textbook at
the end of Chapter 13. Each of the sentences below appears verbatim in the section
entitled Review of Concepts and Vocabulary.
• When naming an alcohol, the parent is the longest chain containing the
__________ group.
• The conjugate base of an alcohol is called an ____________ ion.
• Several factors determine the relative acidity of alcohols, including ___________,
____________, and _______________________.
• The conjugate base of phenol is called a ____________, or _____________ ion.
• Primary and secondary alcohols will undergo an S
N
___ process when treated with
either HX, SOCl
2
, PBr
3
, or when the hydroxyl group is converted into a tosylate
group followed by nucleophilic attack.
• Tertiary alcohols undergo E1 elimination when treated with __________.
• Primary alcohols undergo oxidation twice to give a _____________________.
• Secondary alcohols are oxidized only once to give a ___________
CHAPTER 13
275
Review of Skills
Fill in the blanks and empty boxes below. To verify that your answers are correct, look
in your textbook at the end of Chapter 13. The answers appear in the section entitled
SkillBuilder Review.
13.1 Naming an Alcohol
13.2 Comparing the Acidity of Alcohols
OH OH
Cl
Cl Cl
OH OH
OH OH
FOR EACH PAIR OF COMPOUNDS BELOW, CIRCLE THE COMPOUND THAT IS MORE ACIDIC:
13.5 Preparing an Alcohol via a Grignard Reaction
Ph Et
O
Ph
O
Me
Et
O
Me
Ph Et
OH
Me
IDENTIFY REAGENTS THAT CAN ACHIEVE EACH OF THE FOLLOWING TRANSFORMATIONS
1)
2)
1)
2)
1)
2)
276
CHAPTER 13
13.6 Proposing Reagents for the Conversion of an Alcohol into an Alkyl Halide
OH Cl
IDENTIFY REAGENTS THAT CAN ACHIEVE EACH OF THE FOLLOWING TRANSFORMATIONS
1)
2)
13.8 Converting Functional Groups
IDENTIFY REAGENTS THAT CAN ACHIEVE EACH OF THE FOLLOWING FUNCTIONAL GROUP TRANSFORMATIONS
CHAPTER 13
277
13.9 Proposing a Synthesis
AS A GUIDE FOR PROPOSING A SYNTHESIS, ASK THE FOLLOWING TWO QUESTIONS:
Review of Reactions
Identify the reagents necessary to achieve each of the following transformations. To
verify that your answers are correct, look in your textbook at the end of Chapter 13. The
answers appear in the section entitled Review of Reactions.
Preparation of Alkoxides
ROH RO Na
Preparation of Alcohols via Grignard Reagents
O OH
R
R
O
OMe R
OH
R
R
278
CHAPTER 13
S
N
1 Reactions with Alcohols
R
OH
RR
R
X
R
R
+ H
2
O
S
N
2 Reactions with Alcohols
OH Br
OH Cl
CHAPTER 13
279
R
OH
R
O
H
O
OH O
O
R
OH
R
H
O
Solutions
13.1.
a) 5,5-dibromo-2-methylhexan-2-ol
13.2.
OH
Br
13.3. Nonyl mandelate has a longer alkyl chain than octyl mandelate and is therefore
more effective at penetrating cell membranes, rendering it a more potent agent. Nonyl
280
CHAPTER 13
13.4.
a)
OH Na O Na
13.5.
a)
OH
F F
The electron-withdrawing effects of the fluorine atoms stabilize the conjugate base.
b)
OH
The conjugate base of a primary alcohol will be more easily solvated than the conjugate
base of a tertiary alcohol.
CHAPTER 13
281
e)
OH
The conjugate base is stabilized by resonance.
13.6. 2-nitrophenol is expected to be more acidic (lower pK
a
) because the conjugate
O
NO
OO
NO
O
13.7.
Br OH
H
2
O
d)
OH
1) BH
3
THF
2) H
2
O
2
, NaOH
282
CHAPTER 13
13.8
a)
OH
1) BH
3
THF
2) H
2
O
2
, NaOH
13.9.
a) (+2) (+2). The starting material is neither oxidized nor reduced.
13.10. One carbon atom is reduced from an oxidation state of 0 to an oxidation state of
-1, while the other carbon atom is oxidized from an oxidation state of 0 to an oxidation
13.11. One carbon atom is reduced from an oxidation state of 0 to an oxidation state of
-2, while the other carbon atom is oxidized from an oxidation state of 0 to an oxidation
13.12.
a)
O
H
O
H
HH
O
H
O
H
H Al H
H
H
H
H
CHAPTER 13
283
d)
O
H
O
H
HH
O
H
O
H
H Al H
H
H
H
H
284
CHAPTER 13
13.13.
H Al H
H
H
O
O
O
O
H
H
O
O
H Al H
H
H
H
O
O
H
13.14.
a)
1) MeMgBr
2) H
2
O
1) PrMgBr
2) H
2
O
OH
H
O
H
O
CHAPTER 13
285
d)
1) EtMgBr
2) H
2
O
1)
2) H
2
O
H
O
H
O
OH
MgBr
f)
OMgBr
1) MeMgBr
2) H
2
O
1)
2) H
2
O
OH
O
13.15 Each of the following two compounds can be prepared from the reaction between
a Grignard reagent and an ester, because each of these compounds has two identical
groups connected to the α position:
286
CHAPTER 13
13.16 Each of the following three compounds can be prepared from the reaction
between a hydride reducing agent (NaBH
4
or LAH) and a ketone or aldehyde, because
each of these compounds has a hydrogen atom connected to the α position:
13.17.
O
O
C
H
H
H
MgBr
O
O
CH
3
O
O
CH
3
H
13.18.
a)
Br
HO
TMSCl, Et
3
N1) Mg
2)
O
Br
TMSO TMSO
OH
CHAPTER 13
287
b)
Br
HO Br
TMSO
TMSCl, Et
3
N1) Mg
13.19.
a)
OH Br
1) TsCl, py
2) NaBr
PBr
3
288
CHAPTER 13
d)
OH Br
1) TsCl, py
2) NaBr
PBr
3
f)
OH Br
1) TsCl, py
2) NaBr
PBr
3
HBr
13.20.
OH I
1) TsCl, py
2) NaI
NaCl Cl
CHAPTER 13
289
13.22.
a)
PCC
CH
2
Cl
2
H
OHO
H
OO
H
b)
c)
PCC
CH
2
Cl
2
OH O
H
e)
OH PCC
CH
2
Cl
2
O
13.23.
a)
Br
O
H
1) NaOH
2) PCC, CH
2
Cl
2
290
CHAPTER 13
d)
O
3) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
1) Hg(OAc)
2
, H
2
O
2) NaBH
4
13.24.
a)
OH
2) BH
3
THF
1) H
2
, Lindlar’s Catalyst
1) 9-BBN
2) H
2
O
2
, NaOH
3) LAH
4) H
2
O
3) H
2
O
2
, NaOH
CHAPTER 13
291
d)
H
O
1) BH
3
THF
3) PCC, CH
2
Cl
2
2) H
2
O
2
, NaOH
e)
OH
1) H
2
SO
4
, heat
1) TsCl, py
2) NaOEt
2) H
2
, Pt
3) H
2
, Pt
13.25.
H
2
SO
4
, heat
1) TsCl, py
2) NaOEt
OH
292
CHAPTER 13
13.27.
a)
O
H
O
1) EtMgBr
3) Na
2
Cr
2
O
7
,
H
2
SO
4
, H
2
O
2) H
2
O
13.28.
a)
H
O
OH
PCC
CH
2
Cl
2
O
1) MeMgBr
2) H
2
O
1) Br
2
2) xs NaNH
2
3) H
2
O
1) BH
3
THF
2) H
2
O
2
, NaOH
1) 9-BBN
2) H
2
O
2
, NaOH
3) Na
2
Cr
2
O
7
,
H
2
SO
4
, H
2
O
CHAPTER 13
293
d)
OH
1) TsCl, py
2) t-BuOK
1) BH
3
THF
2) H
2
O
2
, NaOH
OH
f)
OH OH
2) MeMgBr
3) H
2
O
1) Na
2
Cr
2
O
7
,
H
2
SO
4
, H
2
O
13.29.
a)
OH
H
O1) MeMgBr
2) H
2
O
b)
294
CHAPTER 13
c)
Br
C CH Na
H
2
H
O
OH
1) HBr, ROOR
2) NaOH
1) 9-BBN
2) H
2
O
2
, NaOH
1) LAH
2) H
2
O
Lindlar’s
Catalyst
13.30.
a) 2-propyl-1-pentanol
13.31.
a)
OH
O
H
b)
OH
CHAPTER 13
295
d)
O
H
13.32.
HO
OH OH
OH
1-butanol 2-butanol 2-methyl-2-propanol 2-methyl-1-propanol
13.33.
a)
Cl Cl
OH
Cl ClCl Cl
Cl
O
H
Cl Cl
O
H
Increasing acidity
296
CHAPTER 13
13.34.
a)
OO O OO
13.35.
a) 1-bromobutane b) 1-chlorobutane c) 1-chlorobutane d) trans-2-butene
13.36.
O OH
H
H
H O
H
HOHH
OHH
13.37.
CHAPTER 13
297
b)
O
OH
OH Na
2
Cr
2
O
7
H
2
SO
4
, H
2
O
e)
O
OH 1) PCC, CH
2
Cl
2
2) PrMgBr
3) H
2
O
4) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
13.38.
a)
OH
1)
2) H
2
O
HH
OMgBr
298
CHAPTER 13
c)
1) EtMgBr
2) H
2
O
1) PrMgBr
2) H
2
O
OH
H
O
H
O
13.39.
a)
O
H
b)
O
c)
O
d)
O
CHAPTER 13
299
b)
1) LAH
M
e
O
H
13.41.
OBr
O
HHOBr
Br
–
13.42. The major product is 1-methylcyclohexanol (resulting from Markvonikov
13.43.
300
CHAPTER 13
13.44.
PBr
3
OH
OH
O
H
OH
1) MeMgBr
2) H
2
O
1) BH
3
THF
2) H
2
O
2
, NaOH
13.45.
1) TsCl
1) HBr, ROOR
CHAPTER 13
301
13.46.
a)
O O
HH
O
H
O
H Al H
H
H
H
H
13.47.
a)
SOCl
2
Cl
SCl
O
Cl
+ SO
2
+
py Cl
OH Cl
302
CHAPTER 13
b)
OH Br
P Br
Br
Br
OPH
Br
Br
+Br + PBr
2
OH
S
N
2
13.48.
a)
OH
H
2
SO
4
, H
2
O
O
Na
2
Cr
2
O
7
b)
OH PCC
CH
2
Cl
2
O
13.49
CHAPTER 13
303
b)
1) O
3
2) DMS
3) Excess LAH
4) H
2
O
OHHO
d)
1) EtMgBr
3) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
4) EtMgBr
H
O2) H
2
O
5) H
2
O
OH
f)
P
h
OH
1) H
3
O
+
2) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
3) PhMgBr
4) H
2
O
13.50.
304
CHAPTER 13
b)
13.51.
H
O
CH
2
Cl
2
PCC
1) LAH
2) H
2
O
1) 9-BBN
2) H
2
O
2
, NaOH
H
2
, Lindlar’s Catalyst
1) Br
2
2) xs NaNH
2
3) H
2
O
CHAPTER 13
305
13.52.
a)
H
OO
1) MeMgBr
3) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
2) H
2
O
d)
H
O1) MeMgBr
3) TsCl, py
2) H
2
O
4) t-BuOK
306
CHAPTER 13
g)
O
2) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
1) dilute H
2
SO
4
i)
2) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
1) dilute H
2
SO
4
3) MeMgBr
4) conc. H
2
SO
4
, heat
l)
OH
H
O1) EtMgBr
2) H
2
O
CHAPTER 13
307
p)
O1) MeMgBr
2) H
2
O
3) conc. H
2
SO
4
, heat
q)
OH
O1) EtMgBr
2) H
2
O
308
CHAPTER 13
13.53.
HO
13.56.
OH
13.57
O
O
O
O
H Al H
H
H
O
O
O
H
O
O
H
O
O
O
H Al H
H
H
O
H
O
O
H
O
CHAPTER 13
309
13.58
O
O
O
O
C
H
H
H
MgBr
O
O
O
CH
3
O
O
CH
3
O
O
O
C
H
H
H
MgBr
H
O
CH
3
O
O
CH
3
O
13.59
O
1) Br
2
,
hv
2) NaOMe
1) BH
3
THF
2) H
2
O
2
, NaOH
3) Na
2
Cr
2
O
7
, H
2
SO
4
, H
2
O
1) MeMgBr
310
CHAPTER 13
13.60.
O
O
H
H
O
O
H
CH
3
O
O
O
O
H
O
O
O
–
13.61.
HO OH H O S O
O
O
H
HO O
H
H
HO
– H
2
O