Organic Chemistry Questions

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers thequestion.
1) Which term most accurately describes the process shown?
A) coupling
B) hydrogen abstraction
C) halogen abstraction
D) proton transfer
E) homolytic cleavage
2) What is the relationship between the following two compounds?
A) constitutional isomers
C) identical
B) stereoisomers
D) not isomers; different compounds entirely
3) Which synthesis will yield cyclopentanone from 1-methylcyclopentane?
A) t-BuOk followed by 1. Hg(OAc) 2, H2O; 2. NaBH4
B) NaOEt followed by 1. Hg(OAc)2, H2O; 2. NaBH4
C) t-BuOk followed by 1. Hg(OAc) 2 , H2O3 2. NaBH4
D) 1. Br2/CCl4; 2. xs NaNH2; 3. H2O
E) Br2/ hv, followed by KOtBu, followed by 1. O3; 2. DMS
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4) Which of the following sets of reagents accomplishes the transformation shown below?
A) H2/H2SO4
B) H2/Pd
C) H2O/H2SO4
D) H2O/Pd
E) H2/HCl
5) Does a reaction with a positive ∆S and a negative ∆?H favor reactants or products?
A) Reactants
B) Products
C) Neither
D) It is impossible to determine without knowing the temperature
6) Which term most accurately describes the process shown?
A) halogen abstraction
B) elimination
C) hydrogen abstraction
D) homolytic cleavage
E) coupling
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7) Predict the product for the S N2 reaction shown.
A) I
B) II
C) III
D) IV
E) V
D) IV
E) V
D) IV
E) V
8) What is the expected major product of the following reaction?
A) I
B) II
C) III
9) Predict the expected major product of the following reaction.
A) I
B) II
C) III
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10) Predict the sign of ∆S for the following reaction.
A) positive
B) negative
C) no change
11) Select the best reagents for the reaction shown.
A) 1. RCO3H; 2. H3O+
B) 1. O3; 2. DMS
C) 1. OsO4; 2. NaHSO3, H2O
D) 1. BH3-THF; 2. H2O2, NaOH
E) 1. Hg(OAc)2, H2O; 2. NaBH4
12) Which pattern of arrow pushing is involved in the reaction step shown?
A) proton transfer
C) nucleophilic attack
B) loss of leaving group
D) rearrangement
13) Indicate which pattern of arrow pushing it is involved in the reaction step shown.
A) proton transfer
C) nucleophilic attack
B) loss of leaving group
D) rearrangement
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14) Assign the absolute configuration of the chiral center as R or S.
A) R
C) R and S are both possible
B) S
D) The chiral center is neither R or S
15) Which of the mechanistic steps shown represents the loss of a leaving group?
A) I
B) II
C) III
16) Which term most accurately describes the process shown?
A) coupling
B) hydrogen abstraction
C) halogen abstraction
D) addition to a π bond
E) homolytic cleavage
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D) IV
17) Which of the choices is an elimination reaction?
A) I
B) II
C) III
D) IV
18) Select the appropriate synthetic sequence to accomplish the transformation shown.
A) 1. KOtBu; 2. HBr, ROOR; 3. CH3CH2CCNa
B) 1. KOtBu; 2. Br2. hv; 3. CH3CH2CCNa
C) 1. KOtBu; 2. HBr; 3. CH3CH2CCNa
D) 1. KOtBu; 2. HBr, ROOR; 3. CH3CH2CMgBr
E) 1. KOtBu; 2. HBr, ROOR; 3. H3O+
19) What is the expected major product of the reaction sequence shown below?
A) I
B) II
C) III
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D) IV
E) V
20) Which of the alkenes shown below would produce a chiral center upon Markovnikov
hydrohalogenation?
A) I
B) II
C) III
D) IV
E) V
21) What is the nucleophile in the reaction shown?
A) I
B) II
C) III
D) IV
22) What is the expected major organic product from the treatment of 4-methyl-2-pentyne with sodium
metal in liquid ammonia?
A) (Z)-4-methyl-2-pentene
B) (Z)-4-methyl-4-pentene
C) (Z)-2methyl-2-pentane
D) (E)-2-methyl-4-pentene
E) (E)-4-methyl-2-pentene
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23) Which of the alkyl halides shown is essentially unreactive in an SN2 reaction?
A) I
B) II
C) III
D) IV
E) V
24) Identify the expected major product(s) for the following reaction sequence.
A) I
B) II
C) III
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D) IV
E) V
25) Draw the major product of the reaction shown.
A) I
B) II
C) III
D) IV
E) V
D) 4
E) 5
D) IV
E) V
26) How many stereoisomers are there for the compound shown?
A) 1
B) 2
C) 3
27) Select the expected major organic product for the reaction shown.
A) I
B) II
C) III
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28) Which arrow(s) indicates the chiral center(s) in the compound shown?
A) a
B) b
C) a and b
D) d and e
E) b and c
D) IV
E) V
29) Draw the major product of the reaction shown.
A) I
B) II
C) III
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30) What is the expected major final product of the reaction sequence shown?
A) I
B) II
C) III
D) IV
E) None of the shown products will be produced.
31) Select the expected major organic product for the reaction shown.
A) I
B) II
C) III
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D) IV
E) V
32) When drawing a curved arrow mechanism, the tail of the arrow starts at ________.
A) the source of electrons that is being moved
B) the bond that is being formed
C) the atom with the positive charge
D) the location to which the electrons are being moved
33) Predict the expected major product of the following reaction sequence.
A) I
B) II
C) III
D) IV
E) V
D) 35 kJ/mol
E) 15 kJ/mol
34) What is the energy of activation for the following reaction?
A) 30 kJ/mol
B) 10 kJ/mol
C) 20 kJ/mol
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35) Identify the relationship between the following structures.
A) different compounds
C) the same compound
B) enantiomers
D) diastereomers
36) What is the expected major product for the following reaction?
A) I
B) II
C) III
D) IV
E) V
D) IV
E) V
37) What is the expected major product of the following reaction?
A) I
B) II
C) III
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38) Identify the intermediate that would give rise to the product shown in the following reaction.
A) I
B) II
C) III
D) IV
E) V
39) Which of the following alkenes is needed to synthesize the product in the reaction shown below?
A) I
B) II
C) III
D) IV
E) V
40) Identify the relationship between the following structures.
A) enantiomers
B) identical
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C) neither
41) Predict the major product of the reaction shown.
A) I
B) II
C) III
D) IV
42) Select an appropriate synthetic route for the equation given.
A) 1. MCPBA; 2. CH3Br; 3. NaNH2; 4. CH3Br; 5. Na, NH3(l); 6. RCO3H
B) 1. MCPBA; 2. CH3Br r; 3. NaNH2; 4. CH3Br; 5. OsO4; 6. H3O+
C) 1. NaNH2; 2. CH3Br; 3. NaNH2; 4. CH3Br; 5. OsO4; 6. H3O+
D) 2. CH3Br; 2. NaNH2; 3. CH3Br; 4. Na, NH3(l); 5. RCO3H
E) 1. NaNH2; 2. CH3Br; 3. NaNH2; 4. CH3Br; 5. Na, NH3 (l); 6. RCO3H
43) What is the relationship between the following two compounds?
A) constitutional isomers
C) identical
B) stereoisomers
D) not isomers; different compounds entirely
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44) What is the likely product of the SN2 reaction shown?
A) I
B) II
C) III
D) IV
E) None of these
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45) What is the expected major product of the reaction shown?
A) I
B) II
C) III
D) IV
E) V
46) Assign the absolute configuration of the chiral center as R or S.
A) R
C) R and S are both possible
B) S
D) The chiral center is neither R or S
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47) Select the option that correctly shows the movement of electrons during the process shown.
A) I
B) II
C) III
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D) IV
E) V
48) Which of the reactions shown is an example of initiation?
A) I
B) II
C) III
D) IV
E) none of the above
49) Assign the absolute configuration of the chiral center as R or S.
A) R
C) R and S are both possible
B) S
D) The chiral center is neither R or S
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50) Select an appropriate synthesis to lengthen the legs of “Ralph” as shown.
A) 1. NBS, hv; 2. HBr, ROOR; 3. 2 NaCCH; 4. H2, Pt
B) 1. NBS; 2. KCN; 2. HBr, ROOR; 3. 2 NaCCH; 4. H2, Lindlar’s catalyst
C) 1. NBS, hv; 2. KCN; 2. HBr; 3. 2 NaCCH; 4. H2, Pt
D) 1. NBS, hv; 2. KCN; 2. HBr, ROOR; 3. 2 NaCCH; 4. H 2, Lindlar’s catalyst
E) 1. NBS, hv; 2. NaCN; 2. HCl, ROOR; 3. 2 NaCCH; 4. H2, Pt
51) What is the expected major product of the following reaction sequence?
A) I
B) II
C) III
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D) IV
E) V
52) Select the expected major organic product for the reaction shown.
A) I
B) II
C) III
D) IV
E) V
D) IV
E) V
53) Select the expected major organic product for the reaction shown.
A) I
B) II
C) III
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54) What is the IUPAC name for the expected product of the reaction shown?
A) propyne
B) 2-hexyne
C) (E)-3-hexyne
D) 1-hexyne
E) 3-hexyne
55) What major product(s) will be yielded by the elimination reaction shown?
A) I
B) II
C) III
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D) IV
E) I and IV
56) Select the expected major organic product for the reaction shown.
A) I
B) II
C) III
D) IV
E) V
57) Which alkene would yield 3-methylpentane when subjected to catalytic hydrogenation?
A) I
B) II
C) III
D) IV
58) Which sequence of reagents will accomplish the synthesis shown?
A) 1. H2SO4, heat; 2. Br2, hv
B) 1. KOtBu; 2. HBr
C) 1. NaOEt; 2. HBr, ROOR
D) 1. NaOEt; 2. HBr
E) A and D
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E) V
Free response questions
1. Propose an efficient synthesis for each of the following tranformations. You can use
NaCCH or any alkyl halide as a carbon source.
C CH = NaCCH
Na
a.
b.
O
2. Add curved arrows to the structure on the left to indicate the flow of electrons
described by the following mechanistic steps.
H
a.
H
b.
H
H
O
H
c.
O
H
HO
d.
O
O
OH
O
OH
O
3. Fill in each of the boxes below with the letter corresponding to the reagent or set of
reagents best suited to cause the following synthetic transformations. The reagents and
their corresponding letters are listed in the box below.
HO
a.
OH
Br
f.
H
b.
g.
H
2
O
H
Br
c.
OH
h.
Br
OH
d.
i.
Br
e.
HBr
A
B
j.
O
E
Pd/C
ether
Br2
F
1. Hg(OAc)2, H2O/THF
G
2. NaHSO3, H2O
D
2. H2O2, OH-
K
L
I
CH3CH2OH
HBr
ROOR
KMnO4, H3O+
CH3CH2O Na
H2
Lindlar’s cat.
M
1. BH3, THF
1. O3
2. Zn, HOAc
1. OsO4
2. NaBH4
H
J
meta-chloroperbenzoic acid
(mCPBA)
CH2Cl2
C
H2
Na
NH3 (liq)
4. Draw a mechanism for the following reaction using the correct arrow-pushing notation to
indicate the movement of electrons. You may need to draw in lone pairs where necessary.
Some of the carbon atoms have been labeled in the starting material and product to help you.
Note: You can use H+ in place of H2SO4 in your mechanisms.
b
d
O
a
OH
c
c
H2SO4
H 2O
b
a
HO
d