Deck 6: Reactions of Alkenes

Question 1

What is the correct order of stability of the following carbocations (more stable > less stable)?

A)1 > 2 > 3
B)2 > 1 > 3
C)2 > 3 > 1
D)3 > 2 > 1

Answer 1

2 > 3 > 1

Question 2

What is the major organic product obtained from the following reaction?

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

Answer 2

3

Question 3

Which of the following concepts explains why tertiary carbocations are more stable than primary and secondary carbocations?

A)electronegativity
B)resonance
C)hyperconjugation
D)the octet rule

Answer 3

hyperconjugation

Question 4

What is the major organic product obtained from the following reaction?

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

Question 5

What is the major organic product obtained from the following reaction?

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

Question 6

What type of orbitals overlap to provide stability to the tert-butyl carbocation by hyperconjugation?

A)3 ^$\circ$ C 2p atomic orbital + 3 ^$\circ$ C sp² atomic orbital
B)3 ^$\circ$ C 2p atomic orbital + methyl C-H $\sigma$ molecular orbital
C)3 ^$\circ$ C sp² atomic orbital + methyl C-H $\sigma$ molecular orbital
D)3 ^$\circ$ C 2p atomic orbital + methyl C 2s atomic orbital

Question 7

What type of carbocation is shown?

A)primary
B)secondary
C)tertiary
D)quaternary

Question 8

What is the major organic product obtained from the following reaction?

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

Question 9

What is the major organic product obtained from the following reaction?

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

Question 10

Which of the following alkenes is most likely to undergo rearrangement upon acid-catalyzed hydration (treatment with aqueous H₂SO₄)?

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

Question 11

What is the major organic product obtained from the following reaction?

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

Question 12

What type of carbocation is shown?

A)primary
B)secondary
C)tertiary
D)quaternary

Question 13

What is the major organic product obtained from the following reaction?

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

Question 14

Which of the following alkenes is most likely to undergo rearrangement upon acid-catalyzed hydration (treatment with aqueous H₂SO₄)?

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

Question 15

Which of the following concepts explains Markovnikov's rule as applied to the addition of HBr to propene?

A)the relative stability of carbocations
B)the nucleophilicity of bromide anion
C)the acidity of HBr
D)the aufbau principle

Question 16

What is the major organic product obtained from the following reaction?

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

Question 17

What is the correct order of stability of the following carbocations (more stable > less stable)?

A)1 > 2 > 3
B)1 > 3 > 2
C)3 > 1 > 2
D)3 > 2 > 1

Question 18

What is the major organic product obtained from the following reaction?

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

Question 19

What is the major organic product obtained from the following reaction?

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

Question 20

What is the major organic product obtained from the following reaction?

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

Question 21

What is the major organic product obtained from the following reaction?

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

Question 22

What is the major organic product obtained from the following reaction?

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

Question 23

What is the best choice of reagent(s) to perform the following transformation?

A)H₂O, H₂SO₄
B)HgSO₄; followed by NaBH₄
C)BH₃; followed by H₂O₂
D)OsO₄; followed by NaHSO₃

Question 24

What is (are) the major organic product(s) obtained from the following reaction? 1.(2R,3R)-dibromobutane
2)(2S,3S)-dibromobutane
3)meso-2,3-dibromobutane

A)only 1
B)only 2
C)only 3
D)only 1 and 2

Question 25

What is (are) the major organic product(s) obtained from the following reaction? 1.(2R,3R)-dibromobutane 2.(2S,3S)-dibromobutane
3)meso-2,3-dibromobutane

A)only 1
B)only 2
C)only 3
D)only 1 and 2

Question 26

What is the best choice of reagent to perform the following transformation?

A)Br₂
B)HBr
C)Br₂, H₂O
D)N-bromosuccinimide

Question 27

What is the best choice of reagent(s) to perform the following transformation?

A)H₂O, H₂SO₄
B)Hg(OAc)₂ and H₂O ; followed by NaBH₄
C)B₂H₆; followed by H₂O₂, NaOH
D)OsO₄; followed by NaHSO₃

Question 28

What is the major organic product obtained from the following reaction?

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

Question 29

What is the best choice of reagent(s) to perform the following transformation?

A)O₃; followed by (CH₃)₂S
B)Hg(OAc)₂ and H₂O; followed by NaBH₄
C)BH₃; followed by H₂O₂, NaOH
D)OsO₄; followed by NaHSO₃

Question 30

What is the major product obtained upon addition of Br₂ to (R)-4-tert-butylcyclohexene?

A)(1R,2R,4R)-1,2-dibromo-4-tert-butylcyclohexane
B)(1S,2R,4R)-1,2-dibromo-4-tert-butylcyclohexane
C)(1S,2S,4R)-1,2-dibromo-4-tert-butylcyclohexane
D)(1S,2S,4S)-1,2-dibromo-4-tert-butylcyclohexane

Question 31

What is the major organic product obtained from the following reaction?

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

Question 32

What type of reactive intermediate is formed in the reaction of an alkene with HBr to give a bromoalkane?

A)carbocation
B)carbanion
C)radical
D)cyclic bromonium ion

Question 33

What is the best choice of reagent(s) to perform the following transformation?

A)H₂O, H₂SO₄
B)Hg(OAc)₂ and H₂O; followed by NaBH₄
C)BH₃; followed by H₂O₂, NaOH
D)OsO₄; followed by NaHSO₃

Question 34

What is (are) the major organic product(s) obtained from the following reaction?

A)only 1
B)only 2
C)only 3
D)only 1 and 2

Question 35

What is the major organic product obtained from the following reaction?

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

Question 36

What is (are) the major organic product(s) obtained from the following reaction? 1.(2R,3R)-butanediol
2)(2S,3S)-butanediol
3)meso-2,3-butanediol

A)only 1
B)only 2
C)only 3
D)only 1 and 2

Question 37

What is (are) the major organic product(s) obtained from the following reaction?

A)only 1
B)only 2
C)only 3
D)only 2 and 3

Question 38

What is the major organic product obtained from the following reaction?

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

Question 39

What is the major organic product obtained from the following reaction?

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

Question 40

What is the major organic product obtained from the following reaction?

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

Question 41

What type of reactive intermediate is formed in the reaction of an alkene with Br₂ and water to give a bromohydrin?

A)carbocation
B)carbanion
C)radical
D)cyclic bromonium ion

Question 42

Consider the following reaction. The product would be

Question 43

What is the correct order of exothermicity for hydrogenation of the following butenes upon treatment with H₂/Pd (more exothermic > less exothermic)?

A)1 > 2 > 3
B)1 > 3 > 2
C)3 > 2 > 1
D)2 > 3 > 1

Question 44

What type of reaction mechanism accounts for the reaction of an alkene with HBr to give an alkyl bromide?

A)nucleophilic addition
B)electrophilic addition
C)radical addition
D)elimination

Question 45

Which of the following alkenes undergoes the most exothermic hydrogenation upon treatment with H₂/Pd?

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

Question 46

Which of the following alkenes undergoes the least exothermic hydrogenation upon treatment with H₂/Pd?

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

Question 47

Markovnikov addition of HCl to propene involves the formation of a secondary carbocation.

Question 48

Which of the following reactions of alkenes takes place with anti stereospecificity?

A)bishydroxylation (treatment with OsO₄ followed by NaHSO₃)
B)hydrogenation (treatment with H₂/Pt)
C)addition of HBr (treatment with HBr)
D)bromohydrin formation (treatment with Br₂, H₂O)

Question 49

What type of reaction mechanism accounts for the reaction of an alkene with aqueous acid to give an alcohol?

A)nucleophilic addition
B)electrophilic addition
C)radical addition
D)elimination

Question 50

The reagents that could effect the following conversion are H₂ and Ni.

Question 51

The reagents that could effect the following conversion are: BH₃, then H₂O₂ and NaOH.

Question 52

Which of the following reactions of alkenes takes place with syn stereospecificity?

A)addition of bromine (treatment with Br₂)
B)hydrogenation (treatment with H₂/Pt)
C)addition of HBr (treatment with HBr)
D)acid-catalyzed hydration (treatment with aqueous H₂SO₄)

Question 53

What type of reactive intermediate is formed in the reaction of an alkene with aqueous acid to give an alcohol?

A)carbocation
B)carbanion
C)radical
D)carbene

Question 54

Which of the following reactions of alkenes is stereospecific?

A)addition of HCl (treatment with HCl)
B)hydrogenation (treatment with H₂/Pt)
C)addition of HBr (treatment with HBr)
D)acid-catalyzed hydration (treatment with aqueous H₂SO₄)

Question 55

Br₂ in CCl₄ can be used to distinguish cyclohexene from cyclohexane.

Question 56

What is (are) the major organic product(s) obtained from the following reaction? 1.(R)-3-methyl-2-butanol "2.(S)-3-methyl-2-butanol
3)2-methyl-2-butanol"

A)only 1
B)only 2
C)only 3
D)only 1 and 2

Question 57

What is (are) the major organic product(s) obtained from the following reaction? 1.(R)-2-bromo-3-methylbutane
2)(S)-2-bromo-3-methylbutane
3)2-bromo-2-methylbutane"

A)only 1
B)only 2
C)only 3
D)only 1 and 2

Question 58

Consider the following reaction sequence. The product of this sequence is

Question 59

The products obtained by the acid-catalyzed hydration of 1-methylcyclohexene and methylenecyclohexene are identical.

Question 60

Which of the following reactions of alkenes is not stereospecific?

A)bromination (treatment with Br₂ in CHCl₃)
B)hydrogenation (treatment with H₂/Pt)
C)acid-catalyzed hydration (treatment with aqueous H₂SO₄)
D)bromohydrin formation (treatment with Br₂/H₂O)

Question 61

The reaction of methylpropene with HBr in ether gives one of the two products below as the major product. Answer the following question(s) about this reaction.
Product _____ would have the lowest activation energy required to form the intermediate in the mechanism.

Question 62

What is the major organic product obtained from the following reaction?

Question 63

The reaction of methylpropene with HBr in ether gives one of the two products below as the major product. Answer the following question(s) about this reaction.
Product _____ would have a higher energy transition state for the formation of the intermediate leading to it.

Question 64

_____________is the starting material required to produce 3-methyl-1-butanol using the hydroboration-oxidation reaction. (Enter an IUPAC name.)

Question 65

____________________ predicts that the more stable carbocation intermediate is formed in electrophilic additions to alkenes.

Question 66

The reaction of methylpropene with HBr in ether gives one of the two products below as the major product. Answer the following question(s) about this reaction.
Product _____ is the non-Markovnikov product.

Question 67

What is the major organic product obtained from the following reaction?

Question 68

The reaction of methylpropene with HBr in ether gives one of the two products below as the major product. Answer the following question(s) about this reaction.
Product _____would be the major product.

Question 69

Consider the following reactions. Pathway ___ involves a 1,2-shift.

Question 70

What is the major organic product obtained from the following reaction?

Question 71

If the following compound were dissolved in ether and treated with HCl, the product of the reaction would a mixture of 3-bromoheptane and 2-bromoheptane.

Question 72

What is the major organic product obtained from the following reaction?

Question 73

What is the major organic product obtained from the following reaction?

Question 74

What is the major organic product obtained from the following reaction?

Question 75

The reaction of methylpropene with HBr in ether gives one of the two products below as the major product. Answer the following question(s) about this reaction.
Product _____would be formed via a primary carbocation.

Question 76

What is the major organic product obtained from the following reaction?

Question 77

What is the major organic product obtained from the following reaction?

Question 78

Upon ozonolysis, _____________ will produce only acetone, (CH₃)₂C=O. (Enter an IUPAC name.)

Question 79

Consider the following reaction. The mechanism for this reaction is shown below.

Question 80

The reaction of methylpropene with HBr in ether gives one of the two products below as the major product. Answer the following question(s) about this reaction.
Product _____ would be formed by a carbocation experiencing the greatest degree of hyperconjugation stabilization.