SELECTED TOPICS
A STUDENT WHO HAS MASTERED THE MATERIAL IN THIS SECTION SHOULD BE
ABLE TO:
1.
Name given the structure, and draw the structure given the name, of phenols (this is largely
review from the Aromatic Compounds unit).
2.
Predict products of and propose syntheses using the following types of reactions.
Acid-base reactions (primarily review)
Williamson ether synthesis (review from alcohols unit)
Ester formation from phenols (review from carboxylic acid derivatives unit)
Electrophilic aromatic substitution reactions of phenols (primarily review)
Nucleophilic aromatic substitution reactions
Halogenation of aldehydes and ketones
Aldol condensation
Acetoacetic ester synthesis
3.
Propose mechanisms for, and predict and interpret experimental results on the basis of
mechanism, for the following reactions.
Acid-base reactions
Nucleophilic aromatic substitution
Keto-enol tautomerism
Aldol, crossed Aldol, and related condensations
Decarboxylation of beta-keto acids
Acetoacetic ester synthesis
4.
Predict and interpret spectra, solubility test results, and simple chemical test results to
identify unknown compounds.
239
A STUDENT WHO HAS MASTERED THE OBJECTIVES ON THE PREVIOUS PAGE
SHOULD BE ABLE TO SOLVE THE FOLLOWING PROBLEMS AND RELATED ONES:
1.1
Draw the structure of each of the following compounds.
a) o-bromophenol
b) 2,4,6-trimethoxyphenol
1.2
Name each of the following compounds.
OH
a)
CH3
2.1
OH
b)
CH3
NO 2
Predict the product(s) of each of the following reactions.
a)
OH + NH2 - ---->
b)
O- + CH3 C
CH ---->
OH + HNO3
H2 SO 4
--------->
c)
Br
d) O2 N
Cl + CH3 O- --------->
NO 2
O
||
OH –
e) 2 CH3 CH2 C-H -------->
f)
O- + (CH3 )2 CHCH 2 CH2 Br ---->
g)
O
||
acid
C-CH(CH 3 )2 + Br2 ------>
240
2.1
Predict the product, continued.
O
O
CH3 CH2 ONa
CH3 (CH2 )6 Br H3 O , heat
||
||
------------------>
------------------>
---------------->
h) CH3 CCH2 C-O-CH 2 CH3
CH3 CH2 OH
CH3
i)
2.2
Br
NH 2 --------------->
NH 3 , -33ºC
Propose a synthesis of each of the compounds shown, from the starting material(s)
specified and any other needed reagents or solvents.
a)
b)
OCH 2 CH3 from
O
||
CH2 CH2 CCH3
OH and CH3 CH2 OH
from
CH2 Br
O
O
||
||
c) CH3 CH2 CH2 CH from CH3 CH
3.1
a) Which of the following is the strongest acid? b) Which is the strongest base?
A.
3.2
B.
OH
OH
C.
O-
D.
O-
a) Which of the following is the strongest acid? b) Which is the strongest base?
A.
OH
B.
O-
C. CH3
241
OH
D. CH3
O-
3.3
a) Which of the following is the strongest acid? b) Which is the strongest base?
B. CH3 CO2 -
A. CH3 O-
C.
D.
OH
3.4
Draw the structure of each of the species specified.
a) The keto tautomer of phenol
b) The enol tautomer of acetone.
3.5
Propose a mechanism for each of the following reactions.
O
||
a) CH3 C-H
H3 O+
O-H
|
CH2 =C-H
O
||
b) CH3 C-H
OH –
O-H
|
CH2 =C-H
c)
d) O2 N
O
||
C-H
O
||
+ CH3 C-H
OH ------>
Cl + 2 OH- ----> O2 N
242
CO2 H
O
||
CH=CHC-H + H2 O
O- + H2 O + Cl-
3.5
Mechanisms, continued.
O
O
||
||
e) CH3 CCH2 C-OH
4.1
OH–
O
||
CH3 CCH3 + CO2
Which of the following compounds gives a positive iodoform test?
A.
O
CH3
B.
O
C.
OH
CH3
C-CH3
||
O
D.
O
CH2 C-H
||
O
4.2
Of the following compounds, a) which one turns blue litmus red when dissolved in water?
b) Which is neutral to litmus when dissolved it water? c) Which is insoluble in water but
soluble in 5% NaOH (aq) and 5% NaHCO 3 (aq)? d) Which is insoluble in both water and
NaOH (aq)?
CO2 H
OH
OH
D. CH 3 CH2 OH
A.
B.
C.
E. CH3 CO2 H
4.3
Describe a simple chemical test to distinguish between the members in each set. Describe
what you expect to observe.
a) 2-hexanone and 3-hexanone
b) 1-butanol and 2-butanol
c) phenol and cyclohexanol
243
SOLUTIONS TO SAMPLE PROBLEMS:
1.1
a) o-bromophenol
b) 2,4,6-trimethoxyphenol
OH
OH
CH3 O
Br
OCH 3
OCH 3
1.2
a) 3,5-dimethylphenol
2.1
Predict the product:
b) m-nitrophenol or 3-nitrophenol
O- + NH3
a)
OH + NH2 - ---->
b)
O- + CH3 C CH ----> no reaction
c)
OH + HNO3
Br
d) O 2 N
NO 2
H2 SO 4
---------> O2 N
OH +
OH
Br
Br
Cl + CH3 O- ---------> O2 N
OCH 3 + Cl -
NO 2
NO 2
O
OH O
–
||
OH
|
||
e) 2 CH3 CH2 C-H --------> CH3 CH2 CHCHC-H
|
CH3
f)
O- + (CH3 )2 CHCH 2 CH2 Br ---->
OCH 2 CH2 CH(CH 3 )2
+ Br-
g)
O
||
acid
C-CH(CH 3 )2 + Br2 ------>
244
O
||
C-CBr(CH3 )2 + HBr
2.1
Predict the product, concluded. Strictly speaking, only the final product is required for the
answer to problem h); the other products are shown for information purposes only.
O
O
O
O
CH3 CH2 ONa
||
||
||
||
h) CH3 CCH2 C-O-CH 2 CH3 ------------------> CH3 CCHC-O-CH 2 CH3
CH3 CH2 OH
O
O
CH3 (CH2 )6 Br
||
||
------------------> CH3 CCHC-O-CH 2 CH3
CH2 (CH2 )5 CH3
O
H3 O , heat
||
----------------> CH3 CCH2 (CH2 )6 CH3
CH3
i)
2.2
Br
NH 2 --------------->
NH 3 , -33ºC
CH3
CH3
NH 2
+
NH 2
Propose a synthesis:
a)
OCH 2 CH3 from
OH and CH3 CH2 OH
HBr
CH3 CH2 OH -------> CH3 CH2 Br ;
NaOH
OH ------->
ONa + CH3 CH2 Br ------>
b)
O
||
CH2 CH2 CCH3 from
ONa ;
OCH 2 CH3 + NaBr
CH2 Br
O
O
CH2 Br H3 O
CH3 CH2 ONa
||
||
------------------>
--------->
CH3 CCH2 C-O-CH 2 CH3 ------------------>
heat
CH3 CH2 OH
O
||
CH2 CH2 CCH3
245
2.2
Synthesis, concluded
O
O
||
||
c) CH3 CH2 CH2 CH from CH3 CH
O
OH
O
NaOH
heat
||
|
||
------->
------>
2 CH3 CH
CH3 CHCH 2 CH
O
||
CH3 CH=CHCH
O
H2 , Pt
||
--------> CH3 CH2 CH2 CH
3.1
3.2
3.3
a) Strongest acid: B. b) Strongest base: C
a) Strongest acid: A. b) Strongest base: D
a) Strongest acid: D. b) Strongest base: A
3.4
a) The keto tautomer of phenol
b) The enol tautomer of acetone.
OH
|
CH3 C=CH 2
O
H
H
3.5
Mechanisms:
O
||
a) CH3 C-H
H3 O+
O
||
CH3 CH=CHCH
O-H
|
CH2 =C-H
O
+O-H
||
||
+
CH3 C-H + H3 O ----> CH3 CH + H2 O
+O-H
O-H
||
|
CH3 C-H + H2 O ----> CH2 =CH + H3 O+
246
3.5
Mechanisms, continued:
O
||
b) CH3 C-H
OH –
O-H
|
CH2 =C-H
O
O
||
||
CH3 C-H + OH– ----> – CH2 CH + H2 O
O
||
– CH 2 C-H
c)
O–
OH
|
|
CH2 =CH + H2 O ----> CH2 =CH + OH–
O
O
O
OH
||
||
||
C-H + CH3 C-H ------>
CH=CHC-H + H2 O
O
O
||
||
CH3 C-H + OH - ------> H2 O + -CH2 C-H
OO
O
O
||
||
|
||
C-H ---->
-CH2 C-H +
CH -CH2 C-H
OO
|
||
CH-CH2 C-H + H 2 O ------> OH- +
O
OH
|
||
CH -CH2 C-H ---->
247
O
OH
||
|
CH -CH2 C-H
O
||
CH=CHC-H + H2 O
3.5
Mechanisms, concluded.
O- + H2 O + Cl-
Cl + 2 OH- ----> O2 N
d) O2 N
O2 N
O2 N
–
O2 N
O
O
||
||
e) CH3 CCH2 C-OH
Cl + OH---->
Cl
----> O2 N
OH
Cl
O2 N
–
OH + Cl-
OH + OH- ----> O2 N
OH–
OH
O - + H2 O
O
||
CH3 CCH3 + CO2
O
O
O
O
||
||
||
||
–
CH3 CCH2 C-OH + OH ------> CH3 CCH2 C-O– + H2 O
O
O
O
||
||
||
–
CH3 CCH2 C-O -----> CH3 CCH2 – + CO2
O
O
||
||
CH3 CCH2 – + H2 O -----> CH3 CCH3 + OH–
4.1
4.2
4.3
C
a) E b) D c) A d) C
a) Iodoform test: 2-Hexanone would give a positive test (yellow precipitate), and 3hexanone would not react.
b) Iodoform test: 2-butanol would give a positive test (yellow precipitate), and 1- butanol
would not react.
c) Chromic acid test: Cyclohexanol would give a positive test (greenish-opaque solution),
and phenol would not react.
248
Name ___________________________________________________ Ninth Drill Test (Sample)
Organic Chemistry 2220
Answer All Questions
OH
1)
Draw: p-isopropoxyphenol
2) Name:
3)
Predict the product(s) of each of the following reactions (if any):
a)
O- + CH3 CO2 H ---->
b)
H2 O
Cl + NaOH ------->
reflux
C(CH3 )3
O
O
CH2 Br H3 O
CH3 CH2 ONa
||
||
c) CH3 CCH2 C-O-CH 2 CH3 ------------------> ------------------> --------->
heat
CH3 CH2 OH
4)
Which of the following compounds is the weakest acid?
CH2 OH
5)
CO2 H
Which of the following compounds is soluble in 5% NaOH but not in H2 O or 5%
NaHCO 3 ?
CH3
6)
OH
CH2 NH 2
OH
CH2 CO2 H
CH2 OH
CH3
Propose a mechanism for each of the following reactions:
NH 2
a) CH3
Br + NH2
NH 2
+
---->
CH3
CH3
O
NaOH
||
b) H2 C=O + (CH3 )2 CHCHO ---------> (CH 3 )2 C-CH
|
CH2 OH
249
+ Br
Name __________________________________________________ Ninth Drill Test (Sample 2)
Organic Chemistry 2220
Answer All Questions
1)
Draw the structure of 3,5-dinitrophenol.
2)
Which of the following compounds gives a positive iodoform test?
O
||
A. CH3 CCH2 CH3
3)
C. CH3 CH2 CH2 OH
O-
O-
O2 N
CO2 -
Predict the major organic product(s) of the following reactions.
O
OH ||
-------->
a) 2 CH3 CH2 CH2 C-H
OH
b)
5)
6)
O
||
D. CH3 C-OH
Which of the following compounds is the strongest base?
O2 N
4)
OH
|
B. CH3 CH2 CHCH 2 CH3
+
Draw the enol
tautomer of the
ketone shown.
- OH
→
O=
Propose a mechanism for each of the following reactions.
OH
O
|
||
H3 O
a) CH3 C=CH 2
CH3 CCH3
O
O
O
CH3 O
||
||
||
b) 2 CH3 COCH 3 -----------> CH3 CCH2 COCH 3 + CH3 OH
250
CO2 -
Additional sample questions:
1.
Which of the following is an intermediate in the mechanism of the reaction shown?
O
OH O
||
OH –
|
||
2 CH3 CH2 C-H -------> CH3 CH2 CHCHC-H
|
CH3
O
_
||
A. CH2 CH2 C-H
2.
O
_ ||
B. CH 3 CHC-H
O
||
C. CH 2 CH2 C-H
+
O
||
D. CH 3 CHC-H
+
Which of the following compounds is NOT a product of the aldol reaction shown?
O
O
||
||
(CH3 )2 CHC-H + CH3 C-H -----> ?
3.
OH
O
|
||
A. (CH3 )2 CHCHCH 2 C-H
OH
O
|
||
B. CH3 CHCH 2 C-H
OH CH 3 O
|
|
||
C. CH3 CHCH—C
C-H
|
|
CH3
CH3
OH
O
|
||
D. CH3 CHCHC-H
|
CH3 CHCH 3
Which of the following compounds gives a POSITIVE iodoform test?
O
O
||
||
A. CH3 CH2 CCH2 CH3
B. CH3 C-OCH 2
OH
|
C. CH3 CHCH 2
D.
251
OH
|
CH2 CHCH 2 CH3