Deck 6: Reactions of Alkenes

Question 1

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

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

Answer 1

2

Question 2

What type of carbocation is shown?

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

Answer 2

tertiary

Question 3

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

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

Answer 3

3

Question 4

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 5

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

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

Question 6

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

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

Question 7

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

Question 8

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 9

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

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

Question 10

What type of carbocation is shown?

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

Question 11

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

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

Question 12

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

Question 13

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 14

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

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

Question 15

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

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

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 major organic product obtained from the following reaction?

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

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 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 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 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 23

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

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

Question 24

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

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

Question 25

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

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

Question 26

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

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

Question 27

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

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

Question 28

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 29

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

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

Question 30

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 31

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 32

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 33

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

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

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 (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 36

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 37

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 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 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 40

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 41

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 42

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

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

Question 43

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 44

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

Question 45

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 46

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 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

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 52

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

Question 53

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 54

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

Question 55

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 56

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

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

Question 57

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 58

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 59

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 60

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 61

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

Question 62

Provide a neatly drawn mechanism for the following reaction, including curved arrows to show the movement of paris of electrons and the structure of reactive intermediates. The reaction proceeds in two steps:
1. Protonation of propene to form the 2-propyl cation
2. Nucleophilic addition of bromide anion to the 2-propyl cation

Question 63

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

Question 64

Provide a neatly drawn mechanism for the following reaction, including curved arrows to show the movement of paris of electrons and the structure of reactive intermediates. The reaction proceeds in two steps:
1. Addition of bromine to propene to afford a cyclic bromonium ion
2. Nucleophilic ring-opening addition of bromide anion

Question 65

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

Question 66

Provide the structure of the key intermediate in the following reaction?

Question 67

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

Question 68

Provide the structure of the key intermediate in the following reaction?

Question 69

What is the major organic product obtained from the following reaction?
2 equivalents of

Question 70

Provide a neatly drawn mechanism for the following reaction, including curved arrows to show the movement of paris of electrons and the structure of reactive intermediates.

Question 71

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

Question 72

Provide the structure of the key intermediate in the following reaction?

Question 73

Provide a neatly drawn mechanism for the following reaction, including curved arrows to show the movement of paris of electrons and the structure of reactive intermediates. The reaction proceeds in three steps:
1. Protonation of propene to form the 2-propyl cation
2. Nucleophilic addition of bromine to the 2-propyl cation
3. Deprotonation of the oxygen

Question 74

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

Question 75

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

Question 76

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

Question 77

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

Question 78

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

Question 79

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