PRACTICE SECOND HOUR EXAM A
1.
ORGANIC CHEMISTRY 2210
What is (are) the major organic products of the reactions shown?
Br
+ HC
CNa ---> ?
CH3
C
A.
CH
CH3
Na
C.
+ HC
CH3
2.
CBr
B.
CH2 C
D.
CH3 + HC
B.
CH2 CH2 Br
CHBrCH 3
Br
Br
D.
C.
CH2 CH3
CH2 CH3
A sample of (R)-2-pentanol was found to have an optical purity (enantiomeric excess) of
20%. What is the percentage of (S)-2-pentanol in this sample?
A. 10%
4.
CH
Which of the compounds shown gives the fastest SN1 reaction?
A.
3.
CH
B. 20%
C. 40%
D. 80%
What is the configuration of the compound shown?
H
Br
H
Cl
C—C
CH3
A. 2S,3S
CH2 CH3
B. 2S,3R
C. 2R,3S
D. 2R,3R
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5. Which of the following is a meso compound?
A.
H
H
HO
B.
H
C.
OH H
H
H
OH OH
6.
H
A.
B.
C.
D.
H
OH
H
H
Same compound
Enantiomers
Diastereomers
Constitutional isomers
(R)-2-pentanol and (S)-2-pentanol have the same:
A.
B.
C.
D.
rate of reaction with (R)-2-methylbutanoic acid.
rate of reaction with sodium metal.
direction of rotation of plane-polarized light.
enantiomer.
What species is the leaving group in the reaction shown?
Br + 2 CH3 OH ---> Br- + CH3 OH 2+ +
A. CH3 OH
9.
H
OH
HO
OH
HO
8.
OH
OH
What is the relationship between the compounds shown?
H
7.
D. HO
B. CH 3 OH 2 + C. HBr
OCH 3
D. Br –
What is the classification of the reaction shown? Use the representative reaction rate data in
the table below.
(CH3 )3 CI + 2 H2 O ---> (CH3 )3 COH + H3 O+ + I–
Experiment No. [(CH3 )3 CI]
1
2
3
A. SN1
0.01
0.03
0.02
B. SN2
C. E1
[H2 O]
Relative Rate
0.01
0.01
0.03
1
3
2
D. E2
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10. What is the relationship between the structures shown?
CH3
H
CH2 CH3
Cl
H
Cl
CH2 CH3
CH3
A. Same compound
11.
C. Diastereomers
D. Constitutional isomers
The most stable conformer of trans-4-tert-butyl-1-fluorocyclohexane is described by which
of the following?
A.
B.
C.
D.
12.
B. Enantiomers
The tert-butyl group is axial and the fluorine is equatorial.
The tert-butyl group is equatorial and the fluorine is axial.
Both groups are axial.
Both groups are equatorial.
Which of the following reagents give the final product shown when used in the reaction
sequence below and in the order written?
NaNH 2
CH3 I
?
? ----------> --------> ---> (CH3 )3 CCH2 CH2 CH2 CH3
A.
B.
C.
D.
13.
(CH3 )3 CCH2 C≡CH, then H2 , Pt
(CH3 )3 CCH2 C≡CH, then Zn, HCl
(CH3 )3 CCH2 CH2 C≡CH, then H2 , Pt
(CH 3 )3 CCH2 CH2 C≡CH, then Zn, HCl
Which of the following is the best explanation for the relative stabilities of the
conformations shown?
CH3
I
H
H
H
H
CH3
A.
B.
C.
D.
H
H
II
CH3
H
H
CH3
I has more torsional strain.
II has more torsional strain.
I has more steric strain.
II has more steric strain.
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14.
Which of the following gives cyclohexane when reacted with cyclohexene?
A. Zn, HCl B. H2 , Pt C. Br2 , light
15.
D. NaNH2
What is the name of the compound shown?
H
CH3
OH
H
A.
B.
C.
D.
16.
Which of the following SN2 reactions is the FASTEST?
A.
B.
C.
D.
17.
cis-2-methylcyclohexanol
trans-2-methylcyclohexanol
cis-1-methyl-2-cyclohexanol
trans-1-methyl-2-cyclohexanol
CH3 CH2 CH2 Br + OH– ---> CH3 CH2 CH2 OH + Br–
CH3 CHBrCH 3 + OH– ---> CH3 CHOHCH3 + Br–
CH3 CH2 CH2 Br + H2 O ---> CH3 CH2 CH2 OH + HBr
CH 3 CHBrCH 3 + H2 O ---> CH3 CHOHCH3 + HBr
What is the IUPAC name of the given compound?
CH2 CH3
H
H
Cl
CH(CH 3 )2
H
A.
B.
C.
D.
3-chloro-3-ethyl-2-methylbutane
3-chloro-2,3-dimethylpentane
3-chloro-2-methylpentane
3-chloro-3-methylhexane
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18.
Which of the following reactions takes place with retention of configuration?
Cl
A.
H
H
CH3
I---------->
CH3 OH
I
CH3
H
H
CH3
B.
H
Br
C
|
CH2 CH3
CN------->
DMF
CH3
CN
C
H
|
CH2 CH3
CH3
CH3
I
C.
C
CH(CH 3 )2 CH3 OH
------------>
|
CH2 CH3
BH2
H
D.
D.
CH3
C
|
CH2 CH3
+
CH(CH 3 )2
C
OCH 3
|
CH2 CH3
OH
H
H2 O2
---------->
CH3
H
19.
CH3
OCH 3
CH(CH 3 )2
H
Which of the following reaction sequences can be used to perform the conversion shown?
?
?
(CH3 )2 C=CH 2 ----> ----> (CH3 )3 CBr
A.
B.
C.
D.
20.
Br2 , light; then Zn, HBr
Br2 , light; then H2 , Pt
NaNH 2 ; then Br2 , light
H 2 , Pt; then Br2 , light
Which of the following statements about SN1 reactions are TRUE?
I.
II.
III.
A. I only
The reaction rate is independent of the concentration of the
nucleophile.
The nucleophile attacks carbon atoms only on the side of the
molecule opposite the group being displaced.
The reaction proceeds with simultaneous bond formation and
bond rupture.
B. III only
C. I and II
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D. II and III