Deck 9: Addition Reactions of Alkenes

Question 1

The expected major product of the following reaction is:

A)
B)
C)
D)
E)

Answer 1

Question 2

Which of the alkenes below would be expected to produce at least one chirality center upon hydrohalogenation in the presence of peroxide?

A)
B)
C)
D)
E)

Answer 2

Question 3

Addition reactions of alkenes are characterized by:

A) formation of a π bond
B) addition of two groups across a double bond
C) breaking of a π bond
D) A and B
E) B and C

Answer 3

B and C

Question 4

What is the major product for the following reaction?

A)
B)
C)
D)
E)

Question 5

What is the expected major product for the following reaction?

A) I
B) II
C) III
D) IV
E) V

Question 6

Which of the molecules below arises from anti-Markovnikov hydrohalogenation with HBr of the alkene shown?

A)
B)
C)
D)
E)

Question 7

Which of the molecules below would be the expected product for hydrohalogenation of the following alkene with HBr:

A)
B)
C)
D)
E)

Question 8

The expected major product of the following reaction is:

A)
B)
C)
D)
E)

Question 9

In a reaction where addition and elimination reactions are in equilibrium, which of the following statements is most correct?

A) Addition and elimination reactions are favored at low temperatures.
B) Addition and elimination reactions are favored at high temperatures.
C) Only addition reactions are favored at low temperatures.
D) Only elimination reactions are favored at low temperatures.
E) Addition and elimination reactions are disfavored at low temperatures.

Question 10

The decrease in entropy (the $\Delta$ S value is negative) observed for alkene addition reactions results from:

A) the breaking of a π and $\sigma$ bond.
B) the formation of two $\sigma$ bonds.
C) the reaction being exothermic.
D) two molecules reacting to form a single molecule.
E) the temperature dependence of the $\Delta$ S term.

Question 11

Which of the alkenes shown below would produce a chirality center upon Markovnikov hydrohalogenation?

A)
B)
C)
D)
E)

Question 12

In an addition reaction to an alkene, the π bond plays the role of:

A) nucleophile
B) electrophile
C) leaving group
D) A and B
E) B and C

Question 13

In the addition reaction of HI to 2-methyl-2-butene, the Markovnikov addition mechanism involves:

A) attack of 2-methyl-2-butene initiated by an iodide ion.
B) attack of 2-methyl-2-butene initiated by an iodine atom.
C) isomerization of 2-iodo-2-methylbutene.
D) formation of a carbocation at carbon two (C-2).
E) formation of carbocation at carbon three (C-3).

Question 14

Which of the structures shown depicts the most stable carbocation intermediate formed in the hydrohalogenation reaction shown?

A) I
B) II
C) III
D) IV
E) V

Question 15

What compound is the expected product upon Markovnikov hydrohalogenation with HBr of the alkene shown below?

A)
B)
C)
D)
E)

Question 16

The regioselectivity and stereospecificity in hydrohalogenation of an alkene is best described as:

A) Markovnikov orientation with syn-addition
B) Markovnikov orientation with anti-addition
C) anti-Markovnikov orientation with syn-addition
D) anti-Markovnikov orientation with anti-addition
E) Markovnikov orientation with both syn- and anti-addition

Question 17

For an addition reaction, why does free energy, $\Delta$ G, become more positive with increasing temperature?

A) The positive entropy dominates at high temperature.
B) The negative entropy dominates at high temperature.
C) The positive enthalpy dominates at high temperature.
D) The negative enthalpy dominates at high temperature.
E) The enthalpy and entropy cancel at high temperature.

Question 18

For this question, the "entropy term" refers to "-TΔS". Addition reactions are generally favorable at low temperatures because:

A) the positive enthalpy term is larger than the negative entropy term.
B) the negative enthalpy term is larger than the positive entropy term.
C) the positive enthalpy term is smaller than the negative entropy term.
D) the negative enthalpy term is smaller than the positive entropy term.
E) the enthalpy and entropy terms are equal.

Question 19

Which statement best describes the temperature dependence of an addition reaction?

A) Addition reactions are thermodynamically favored at all temperatures.
B) Addition reactions are thermodynamically disfavored at all temperatures.
C) Addition reactions are thermodynamically favored at low temperatures.
D) Addition reactions are thermodynamically favored at high temperatures.
E) Addition reactions are thermodynamically impossible.

Question 20

The expected Markovnikov addition product of HI to 2-methyl-2-butene is:

A) 2-iodopentane
B) 2-iodo-2-methylbutane
C) 1-iodo-2-methylbutane
D) 1-iodo-3-methylbutane
E) 2-iodo-3-methylbutane

Question 21

Treatment of 1-methylcyclohexene with H₃O⁺ would be expected to yield as the major product which of the molecules below?

A) I and III
B) II
C) III and V
D) IV
E) I, III and V

Question 22

The expected major product of the following reaction is:

A)
B)
C)
D)
E)

Question 23

The expected major product(s) of HBr addition to the alkene shown would be:

A)
B)
C)
D)
E)

Question 24

What is the expected major product for the following reaction?

A)
B)
C)
D)
E)

Question 25

The expected major product of the following reaction is:

A) I
B) II
C) III
D) IV
E) V

Question 26

Select the expected major product(s) of the following reaction:

A)
B)
C)
D) A and B
E) A and C

Question 27

What would be the optimal conditions to effect the following transformation?

A) Dilute H₂SO₄
B) Concentrated H₂SO₄
C) Dilute HBr
D) Concentrated HBr

Question 28

Which of the following carbocations is (are) likely to undergo rearrangement through a hydride shift?

A) I
B) II
C) III
D) I and II
E) II and III

Question 29

Which of the following carbocations is (are) likely to undergo rearrangement through a methyl shift?

A) I
B) II
C) III
D) I and II
E) II and III

Question 30

Which of the following compounds would react most rapidly with a dilute aqueous solution of H₂SO₄?

A) I
B) II
C) III
D) IV

Question 31

The reaction shown below would be expected to produce as major products which of the following compounds?

A)
B)
C)
D)
E)

Question 32

What is the IUPAC name of the expected major product formed upon reaction of HCl with 3-methyl-1-butene?

A) 1-chloro-2-methylbutane
B) 1-chloro-3-methylbutane
C) 2-chloro-2-methylbutane
D) 2-chloro-3-methylbutane
E) 1-chloropentane

Question 33

Identify the expected product(s) for the reaction shown below:

A)
B)
C)
D)
E)

Question 34

Which of the given reaction schemes would produce the molecule shown below?

A)
B)
C)
D) Both A and B
E) Both B and C

Question 35

The regioselectivity and stereospecificity in the acid-catalyzed hydration of an alkene is best described as:

A) Markovnikov orientation with syn-addition
B) Markovnikov orientation with anti-addition
C) anti-Markovnikov orientation with syn-addition
D) anti-Markovnikov orientation with anti-addition
E) Markovnikov orientation with both syn- and anti-addition

Question 36

What would be the optimal conditions to effect the following transformation?

A) Dilute aqueous H₂SO₄
B) Concentrated H₂SO₄
C) Dilute aqueous HBr
D) Concentrated HBr

Question 37

Which of the molecules below are enantiomers formed as products upon reaction of HBr with 4-methylpent-1-ene?

A) I and II
B) II and III
C) III and IV
D) I and III
E) II and IV

Question 38

The three compounds below can form a carbocation under aqueous acidic conditions. Which ones will form the same carbocation?

A) I and II
B) I and III
C) II and III
D) All three will form the same carbocation

Question 39

The expected major product(s) of HCl addition to the alkene shown would be:

A) II
B) II and III
C) I and IV
D) V
E) All of the above are equally likely to form

Question 40

The expected major product of the following reaction is:

A) I
B) II
C) III
D) IV
E) V

Question 41

What is the expected product for the hydrogenation of an alkene?

A) dihaloalkane
B) alkane
C) haloalkane
D) alcohol
E) ether

Question 42

The regioselectivity and stereospecificity in the oxymercuration of an alkene is best described as:

A) Markovnikov orientation with syn-addition
B) Markovnikov orientation with anti-addition
C) anti-Markovnikov orientation with syn-addition
D) anti-Markovnikov orientation with anti-addition
E) Markovnikov orientation with both syn- and anti-addition

Question 43

What is the expected major product for the following reaction sequence?

A)
B)
C)
D)
E)

Question 44

What is the expected major product for the following reaction?

A)
B)
C)
D)
E)

Question 45

Which of the following is the major product of the reaction shown?

A) I
B) II
C) III
D) IV

Question 46

When an alkene is subjected to treatment with Hg(OAc)₂ in alcohol, followed by reaction with NaBH₄, what functional group is formed?

A) ether
B) epoxide
C) alkane
D) syn diol
E) alkyne

Question 47

What reagents are needed to accomplish the following transformation?

A) H₂O/H⁺
B) H₂O/Peroxide
C) OH^-
D) BH₃^.THF
E) 1. BH₃^.THF, 2. HO^-, H₂O₂, H₂O

Question 48

What is (are) the expected major product(s) for the following reaction sequence?

A) I
B) II
C) III
D) I and II
E) I and III

Question 49

What is the expected major product for the following reaction?

A)
B)
C)
D)
E)

Question 50

What is the expected major product for the following reaction sequence?

A)
B)
C)
D)
E)

Question 51

Which of the following correctly describes the product(s) of the reaction below?

A) Only one stereoisomer
B) An equal mixture of enantiomers
C) A roughly equal mixture of diasteromers
D) A roughly equal mixture of constitutional isomers

Question 52

What product is formed when trans-1,2-dimethylcyclohexane is reacted with Pd/C and H₂?

A) No reaction
B) cis-1,2-dimethylcyclohexane
C) trans-3,4-dimethylhexane
D) trans-1,2-dimethylhexane
E) None of the above

Question 53

What is the expected major product for the following reaction sequence?

A)
B)
C)
D)
E)

Question 54

What is the expected major product for the following reaction?

A)
B)
C)
D)
E)

Question 55

What is the expected major product for the following reaction?

A)
B)
C)
D)
E)

Question 56

What synthetic goal is achieved by subjecting an alkene to an oxymercuration-demercuration reaction sequence?

A) Markovnikov addition of H₂O, promoting skeletal rearrangement
B) Markovnikov addition of H₂O, preventing skeletal rearrangement
C) anti-Markovnikov addition of H₂O, promoting skeletal rearrangement
D) anti-Markovnikov addition of H₂O, preventing skeletal rearrangement
E) anti-Markovnikov addition of H₂O, syn-hydroxylation

Question 57

What is the name of the product formed when 5-chloro-1-methylcyclohexene is reduced with a Pt catalyst and H₂?

A) 1-chloro-2-methylcyclohexane
B) 1-chloro-3-methylcyclohexane
C) 1-chloro-5-methylcyclohexane
D) 3-chloro-1-methylcyclohexane
E) None of the above

Question 58

The regioselectivity and stereospecificity in the hydroboration-oxidation of an alkene is best described as:

A) Markovnikov orientation with syn-addition
B) Markovnikov orientation with anti-addition
C) Anti-Markovnikov orientation with syn-addition
D) Anti-Markovnikov orientation with anti-addition
E) Markovnikov orientation with both syn- and anti-addition

Question 59

Provide the organic product(s) for the reaction shown below.

A)
B)
C)
D)
E)

Question 60

What is the expected major product for the following reaction sequence?

A) I
B) II
C) III
D) IV
E) V

Question 61

What is the expected major product upon reaction of 1-pentene with Cl₂?

A) 1-chloropentane
B) 2-chloropentane
C) 1,1-dichloropentane
D) 2,2-dichloropentane
E) 1,2-dichloropentane

Question 62

For the complete reduction of 1 mole of (3E,5E)-hepta-1,3,5-triene with H₂ using a Pd catalyst, how many moles of H₂ are consumed?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 63

Wilkinson's catalyst accomplishes which of the listed molecular transformations?

A) syn addition of H₂ to an alkene
B) anti addition of H₂ to an alkene
C) syn dihydroxylation of an alkene
D) anti dihydroxylation of an alkene
E) oxidative cleavage of an alkene

Question 64

Which of the catalysts listed are used in the homogenous catalytic hydrogenation of alkenes? I) Ni II) Pt III) Wilkinson's catalyst

A) I
B) II
C) III
D) I and II
E) II and III

Question 65

Treating 2-methyl-2-pentene with Br₂ is expected to produce which of the following as the major product?

A) 2,3-dibromo-2-methylpentane
B) 2,2-dibromo-3-methylpentane
C) 3,3-dibromo-2-methylpentane
D) 2-bromo-2-methylpentane
E) 3-bromo-2-methylpentane

Question 66

The expected first intermediate formed during a halohydrin reaction is:

A) a halonium ion.
B) the most stable carbocation with OH on the adjacent carbon.
C) the most stable carbocation with X on the adjacent carbon.
D) a cyclic oxonium ion.
E) the most stable carbanion.

Question 67

What is the expected major product for the following reaction?

A) I
B) II
C) III
D) IV
E) V

Question 68

Which of the statements is most correct regarding the products expected from the halogenation reaction shown below?

A) Equal amounts of I and II are produced.
B) Equal amounts of III and IV are produced.
C) Equal amounts of I and IV are produced.
D) Equal amounts of II and III are produced.
E) Equal amounts of I and III are produced.

Question 69

The reaction of Br₂ with 1-methylcyclohexene, in the presence of ethylamine (EtNH₂), is expected to produce which of the following as the major product?

A) I
B) II
C) III
D) IV
E) V

Question 70

How many moles of hydrogen (H₂) are consumed in the catalytic reduction of 1 mole of 1,3-dibromocyclohexa-1,4-diene?

A) 12
B) 2
C) 3
D) 4
E) None of the above

Question 71

What major product is expected from the following reaction?

A) I
B) II
C) III
D) IV
E) V

Question 72

How many moles of hydrogen (H₂) are required to completely reduce 1 mole of cis-2,3,3-trimethylhepta-1,5-diene?

A) 02
B) 1
C) 2
D) 3
E) 4

Question 73

In conducting a catalytic hydrogenation of an alkene, which catalyst listed is most likely soluble in the reaction medium?

A) Ni
B) Pt
C) Pd
D) Wilkinson's catalyst
E) All of the above are soluble

Question 74

Which of the following sets of reagents accomplishes the transformation shown below?

A) H₂/HCl
B) H₂/H₂SO₄
C) H₂/Ni
D) H₂O/Ni
E) H₂O/H₂SO₄

Question 75

Identify the major organic product generated from the reaction shown.

A) I
B) II
C) III
D) IV

Question 76

Which alkene would yield 3-methylpentane upon subjection to catalytic hydrogenation?

A) I
B) II
C) III
D) IV
E) V

Question 77

For the catalytic hydrogenation of alkenes, select from below those most likely to function as a homogenous catalyst?

A) Wilkinson's catalyst
B) Ni
C) Pd
D) Pt
E) Au

Question 78

Which reaction intermediate is formed when 4?methylcyclohexene reacts with Br₂ dissolved in CCl₄?

A) I
B) II
C) III
D) IV
E) V

Question 79

Which of the following will yield 2-methylpentane upon catalytic hydrogenation?

A) 2-methyl-1-pentene2
B) 2-methyl-2-pentene
C) 4-methyl-2-pentene
D) 4-methyl-1-pentene
E) All of the above

Question 80

Which of the reagents below are expected to convert cyclopentene into cyclopentane?

A) H₂ and Ni
B) H₂O
C) Heat
D) Zn, H₃O⁺
E) Light