Deck 6: The Reactions of Alkenes - the Stereochemistry of Addition Reactions

Question 1

Draw the structures of the two alkenes that react with HBr to yield 1-bromo-1-methylcyclopentane as the major organic product.

Answer 1

Question 2

Which of the following is the most stable carbocation?

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

Answer 2

IV

Question 3

Complete the following reaction and provide a detailed,step-by-step mechanism for the process.

Answer 3

Question 4

Draw the major organic product generated in the reaction below.

Question 5

What is hyperconjugation,and how does it affect carbocation stability?

Question 6

Draw the major organic product generated in the reaction below.

Question 7

Based on the relative stabilities of the intermediates involved,explain the basis for Markovnikov's rule in the addition of hydrogen halides to alkenes.

Question 8

For an endergonic reaction step,the Hammond postulate allows one to say that

A)the transition state of the step resembles the reactants of the step.
B)the transition state of the step resembles the products of the step.
C)the step is rate-determining since it has the smallest E_a.
D)the reaction containing this step is overall first order.
E)the transition state is precisely symmetric with bond-breaking and bond-forming occurring to the same extent.

Question 9

According to the Hammond Postulate,which of the following is correct?

A)The transition state of an endothermic reaction step will be more reactant-like than product-like.
B)The intermediate of an endothermic reaction step will be more reactant-like than product-like.
C)The transition state of an exothermic reaction step will be more reactant-like than product-like.
D)All transition states are more product-like than reactant-like.
E)All transition states are more reactant-like than product-like.

Question 10

Draw the major organic product generated in the reaction below.

Question 11

Provide the structure of the major organic product in the reaction below.

Question 12

Draw the major organic product generated in the reaction below.

Question 13

Draw the product.

Question 14

Which of the following compounds will react most rapidly with HCl?

A)5-methyl-1-hexene
B)4-methyl-1-hexene
C)(E)-5-methyl-2-hexene
D)(E)-2-methyl-3-hexene
E)2-methyl-2-hexene

Question 15

Draw the major organic product generated in the reaction below.

Question 16

Provide the structure of the major organic product in the reaction below.

Question 17

Which alkene reacts the fastest with HBr?

A)
B)
C)
D)
E)

Question 18

Draw the major organic product generated in the reaction below.

Question 19

Identify the most stable carbocation.

A)
B)
C)
D)
E)

Question 20

Which of the following alkenes reacts with HCl at the slowest rate?

A)
B)
C)
D)
E)

Question 21

Provide the structure of the major organic product in the reaction below.

Question 22

Provide the major organic product(s)in the reaction below.

Question 23

Complete the following reaction and provide a detailed,step-by-step mechanism for the process.

Question 24

What is the major product from the acid-catalyzed hydration of 2-methyl-2-pentene?

A)2-methylpentane
B)2-methyl-1-pentanol
C)2-methyl-2-pentanol
D)2-methyl-3-pentanol
E)1-methoxypentane

Question 25

What is the major product of the following reaction?

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

Question 26

Which is more highly regioselective the addition of HCl to methylenecyclohexane or to 1-methylcyclohexene? Explain.

Question 27

Draw the major organic product generated in the reaction below.

Question 28

Provide the structure of the major organic product of the following reaction.

Question 29

Which of the following alkenes yield(s)3-bromo-3-methylpentane as the major product upon addition of HBr?

A)I and II only
B)III only
C)I,II,and III only
D)all of them
E)none of them

Question 30

Identify the true statements in the mechanism in the addition of water to an alkene.

A)The addition of the electrophile is a slow step.
B)The addition of the nucleophile is a fast step.
C)A carbocation is formed as an intermediate.
D)Water abstracts the extra proton from the protonated alcohol.
E)all of the above

Question 31

Draw the product.

Question 32

Propose a mechanism for the following reaction:

Question 33

Provide the structure of the major organic product in the reaction below.

Question 34

Provide the structure of the major organic product of the following reaction.

Question 35

Provide the major organic product(s)in the reaction below.

Question 36

Draw the major organic product generated in the reaction below.

Question 37

Draw the major organic product generated in the reaction below.

Question 38

Draw the product.

Question 39

Which of the following carbocations is likely to rearrange?

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

Question 40

Give the product for the reaction of 1-butene with methanol in the presence of acid.

A)1-ethoxybutane
B)2-ethoxybutane
C)1-methoxybutane
D)2-methoxybutane
E)1-butanol

Question 41

Draw the major organic product generated in the reaction below.

Question 42

Provide the major organic product(s)in the reaction below.

Question 43

Draw the major organic product generated in the reaction below.

Question 44

Which statement is true in the hydroboration-oxidation of an alkene?

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

Question 45

Give the major organic product of the reaction shown.

A)
B)
C)
D)
E)

Question 46

Draw the structure of the major product of the reaction below.

Question 47

Complete the following reaction and provide a detailed,step-by-step mechanism for the process.

Question 48

What reagents are needed to accomplish the following transformation?

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

Question 49

Draw the major organic product generated in the reaction below.

Question 50

What is the major product of the following reaction?

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

Question 51

What is the name of the major organic product of the following reaction?

A)3,3-dimethyl-1-butanol
B)3,3-dimethyl-2-butanol
C)2,3-dimethyl-2-butanol
D)2,3-dimethyl-1-butanol
E)4-methyl-2-pentanol

Question 52

Which reaction intermediate is formed when Br₂/CCl₄ reacts with cyclohexene?

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

Question 53

Provide a detailed,step-by-step mechanism for the reaction shown below.

Question 54

Provide the major organic product in the reaction below.

A)
B)
C)
D)
E)

Question 55

Provide the major organic product(s)in the reaction below.

Question 56

Draw the major organic product generated in the reaction below.

Question 57

Provide the major organic product(s)in the reaction below.

Question 58

Provide the major organic product(s)in the reaction below.

Question 59

Provide the structure of the major organic product in the reaction below.

Question 60

Provide the major organic product(s)in the reaction below.

Question 61

Give the product for the reaction that occurs when 1-pentene is treated with Cl₂.

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

Question 62

Provide the major organic product in the reaction below.

A)
B)
C)
D)
E)

Question 63

Provide the structure of the major organic product in the reaction below.

Question 64

Complete the following tree of reactions by giving the major products:

Question 65

Which of the following is the most stable alkene?

A)
B)
C)
D)
E)

Question 66

Provide the structure of the major organic product in the reaction below.

Question 67

Provide the structure of the major organic product of each of the following reactions.

Question 68

Provide the structure of the major organic product in the reaction below.

Question 69

What configurations are found in the product(s)of the reaction below?

A)1R,2R only
B)1S,2S only
C)1R,2S only
D)an equal mixture of 1R,2R and 1S,2S
E)an equal mixture of 1R,2R and 1R,2S

Question 70

What is the product of the hydrogenation of an alkene?

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

Question 71

Provide the structure of the major organic product in the reaction below.

Question 72

Upon hydrogenation,which of the following alkenes releases the least heat per mole?

A)3,4-dimethyl-1-hexene
B)(Z)-3,4-dimethyl-2-hexene
C)(E)-3,4-dimethyl-2-hexene
D)(Z)-3,4-dimethyl-3-hexene
E)(E)-3,4-dimethyl-3-hexene

Question 73

Give the types of products formed from the bromination and catalytic hydrogenation (using D₂)of cyclohexene.

Question 74

Draw the product.

Question 75

Provide the major organic product(s)in the reaction below.

Question 76

Give the intermediate for the halohydrin reaction.

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 77

Which of the following reagents gives the reaction shown below? CH₃CH= CH₂ + ? → CH₃CH₂CH₃

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

Question 78

Identify the products of cis-3-methyl-3-hexene with hydrogen bromide.

A)(2R,3S)-3-bromo-3-methylhexane
B)(2R,3R)-3-bromo-3-methylhexane
C)(2S,3R)-3-bromo-3-methylhexane
D)(2S,3S)-3-bromo-3-methylhexane
E)all of the above answers

Question 79

Draw the products.

Question 80

Which of the following alkenes would have the smaller heat of hydrogenation? Explain.
CH₂
CH₂ or CH₃CH CH₂