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Chapter 10 Multiple Choice Questions: Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Easy 1. For the molecule below, known as 2-pentyne, which of the following describes the
orbital overlap of the C2—C3 sigma bond? C CCH3 CH2CH3
A) sp–sp B) sp2–sp2 C) sp3–sp3 D) p–p E) sp3–sp Ans: A
Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Easy 2. For the molecule below, known as 2,4-hexadiyne, which of the following describes
the orbital overlap of the C3—C4 sigma bond? H3C C C C C CH3 A) sp–sp B) sp2–sp2 C) sp3–sp3 D) p–p E) sp3–sp Ans: A
Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Easy 3. The sigma bond of an alkyne is formed from the overlap of which orbitals?
A) sp3–sp3 B) p–p C) sp2–sp2 D) s–s E) sp–sp Ans: E
Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Easy 4. What is the hybridization of the carbon atoms numbered 1 and 2 respectively in the
following structure?
CCCCH
H
H 1 2
A) sp3, sp2
B) sp2, sp2 C) sp, sp D) sp2, sp E) sp, sp2 Ans: D
Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Easy 5. The C≡C bond of an alkyne is composed of which bond types?
A) three anti-bonds B) three σ bonds C) two σ bonds and one π bond D) one σ bond and two π bonds E) three π bonds Ans: D
Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Easy 6. Which of following statements best describes the general reactivity of alkynes?
A) An alkyne reacts as a nucleophile, and is therefore electron rich. B) An alkyne reacts as a nucleophile, and is therefore electron poor. C) Alkynes fail to undergo electrophilic addition reactions, unlike alkenes. D) An alkyne reacts as an electrophile, and is therefore electron rich. E) An alkyne reacts as an electrophile, and is therefore electron poor. Ans: A
Topic: Introduction to Alkynes Section: 10.1 Difficulty Level: Moderate 7. Which of the following statements is true about propyne, H–C≡C–CH3?
A) It contains 3 sigma bonds. B) It contains three pi bonds. C) The H–C≡C bond angle is about 109.5°. D) The C≡C–C bond angle is 180°. E) All carbon-carbon bonds are of equal length. Ans: D
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 8. What is the correct IUPAC name for the molecule shown below?
H2C C C CH2C
BrCH3
CH3H3C
A) 6-Bromo-3-octyne B) 6-Bromo-6-methyl-3-heptyne C) 2-Bromo-2-methyl-4-heptyne D) 6-Bromo-6,6-dimethyl-3-hexyne E) 2-Bromo-4-octyne Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 9. What is the correct IUPAC name for the molecule shown below?
C CHCH2CH3
CH2CH3CCH3CH2
A) 1,1-Diethyl-2-pentyne B) 3-(1-Butynyl)pentane C) 5-Ethyl-3-octyne D) 3-Ethyl-4-heptyne E) 5-Ethyl-3-heptyne Ans: E
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy
10. What is the correct IUPAC name for the molecule shown below?
C CHCH2CH2CH3
CH2CH3CHCH3C
H3C
A) 2-Methyl-5-propyl-3-heptyne B) 5-Ethyl-2-methyl-3-octyne C) 1-Isopropyl-3-ethyl-1-hexyne D) 6-Methyl-3-propyl-4-heptyne E) 4-Ethyl-7-methyl-5-octyne Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 11. What is the correct IUPAC name for the molecule shown below?
CC
H3CCH3
CH3HCCH3C
CH3
A) 2,2,3-Trimethyl-4-hexyne B) 4-tert-Butyl-2-pentyne C) 4,5,5-Trimethyl-2-hexyne D) 4,5,5,5-Tetramethyl-2-pentyne E) 2,2-Dimethyl-3-(1-propynyl)butane Ans: C
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 12. What is the correct IUPAC name for the molecule shown below?
A) 5,6,6-Trimethyl-1-heptyne B) 5-tert-Tutyl-1-hexyne C) 2,2,3-Trimethyl-6-heptyne D) 2,2,3-(3-Butynyl)butane E) sec-Butyl-tert-butylacetylene Ans: A
Topic: Nomenclature of Alkynes Section: 10.2
Difficulty Level: Easy 13. What is the correct IUPAC name for the molecule shown below?
ClCl
Cl
A) 1,1,1-Trichloro-4-hexyne B) 4,4,4-Trichloro-1-butyne C) 1,1,1-Trichloro-2-butyne D) 5,5,5-Trichloro-2-pentyne E) 6,6,6-Trichloro-2-hexyne Ans E
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 14. What is the correct IUPAC name for the molecule shown below?
A) 4,4-Dimethyl-2-pentyne B) 2,2-Dimethyl-4-heptyne C) 1-tertButyl-3-heptyne D) 6,6-Dimethyl-3-heptyne E) 6,6,6-Trimethyl-3-hexyne Ans: D
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 15. What is the correct IUPAC name for the molecule shown below?
A) 4-Ethyl-2-pentyne B) 2-Ethyl-3-pentyne C) 3-Methyl-4-hexyne D) 4-Methyl-2-hexyne E) sec-Butylpropyne Ans: D
Topic: Nomenclature of Alkynes Section: 10.2
Difficulty Level: Easy 16. Which of the following is an acceptable structure for hepta-3,6-dien-1-yne?
I II III IV V A) I B) II C) III D) IV E) V Ans: A
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 17. Which of the following is an acceptable structure for 2-hexyne?
I II III IV V A) I B) II C) III D) IV E) V Ans: D
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 18. Which of the following is an acceptable structure for 3-sec-butyl-1-heptyne?
I II III IV V A) I B) II C) III D) IV E) V Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 19. Provide the systematic IUPAC name for BrCH2CH2C≡CCH2CH3.
A) 1-Bromo-3-hexyne B) 6-Bromo-3-hexyne C) 1-Bromo-2-hexyne D) 6-Bromo-4-hexyne E) 1-Bromo-4-hexyne Ans: A
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 20. Provide the systematic IUPAC name for HC≡CCH2CH2CH3.
A) Pentyne B) 1-Pentyne C) Butyne D) 1-Butyne E) 2-Butyne Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Easy 21. Provide the systematic IUPAC name for Cl3CCH2CH2CH2C≡CH.
A) 6,6,6-Trichloro-1-hexyne B) 1,1,1-Trichloro-5-hexyne C) 5,5,5-Trichloro-1-pentyne D) 1-Heptyne E) Trichlorobutylacetylene Ans: A
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 22. Provide the systematic IUPAC name for Cl3C(CH2)4C≡CH.
A) 4,4,4-Trichloro-1-butyne
B) 1,1,1-Trichloro-6-heptyne C) 1,1,1-Trichloro-5-heptyne D) 6,6,6-Trichloro-1-hexyne E) 7,7,7-Trichloro-1-heptyne Ans: E
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 23. Provide the systematic IUPAC name for (CH3)2CHC≡CCH2C(CH3)3.
A) 1,1,5,5,5-Pentamethyl-2-pentyne B) 1,1,1,5,5-Pentamethyl-3-pentyne C) 2,2,6-trimethyl-4-heptyne D) 2,6,6-trimethyl-3-heptyne E) tert-butylisopropylacetylene Ans: D
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 24. Provide the systematic IUPAC name for the molecule below:
CH3C(CH3)2CH2C≡CCH2CH(CH2CH3)CH3 A) 2,7,7-Trimethyl-5-nonyne B) 2-Ethyl-7,7-dimethyl-4-octyne C) 2,2,7-Trimethyl-4-nonyne D) 7-Ethyl-2,2-trimethyl-4-octyne E) 6-Undecyne Ans: C
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 25. What is the correct IUPAC name for the molecule shown below?
Br A) 3-Bromo-4-acetylenyl-heptane B) 3-(1-Bromopropyl)-1-hexyne C) 3-Bromo-4-propyl-5-hexyne D) 4-Bromo-3-propyl-1-hexyne
E) 4-Ethynyl-5-bromo-heptane Ans: D
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 26. Which of the following is an acceptable structure for (R)-5-bromohept-2-yne.
I II III IV V
BrBr
BrBr Br
A) I B) II C) III D) IV E) V Ans: E
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 27. What is the correct IUPAC name for the molecule shown below?
A) (E)-5-methyl-5-hepten-1-yne B) (Z)-5-methyl-5-hepten-1-yne C) (E)-3-methyl-2-hepten-6-yne D) (Z)-3-methyl-2-hepten-6-yne E) (E)-2-butynyl-2-butene Ans: A
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 28. What is the correct IUPAC name for the molecule shown below?
A) (E)-4-isopropyloct-3-en-5-yne B) (Z)-4-isopropyloct-3-en-5-yne C) (E)-5-isopropyloct-5-en-3-yne
D) (Z)-5-isopropyloct-5-en-3-yne E) (E)-4-(2-methylethyl)oct-3-en-5-yne Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 29. Which structure shown below represents (Z)-3,5-dichloro-3-hexen-1-yne?
ClI II III IV
Cl
ClClCl
Cl
Cl
Cl
A) I B) II C) III D) IV E) I and II are both correct Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 30. Which of the following is an acceptable structure for (2E,4E)-octa-2,4-dien-6-yne?
I II III IV V A) I B) II C) III D) IV E) V Ans: D
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 31. Which of the following is an acceptable structure for octa-3,6-dien-1-yne?
A) HC≡CCH=CHCH=CHCH2CH3 B) CH3CH=CHCH2C≡CC≡CH
C) CH3CH=CHCH2CH=CHC≡CH D) CH3C≡CCH=CHCH=CHCH3 E) H2C=CHC≡CCH2CH=CHCH3 Ans: C
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Moderate 32. Which of the following is an acceptable structure for 2,5,5-trimethylhept-3-yne
A) (CH3CH2)CH(CH3)C≡CCH2CH(CH3)2 B) (CH3CH2)C(CH3)2C≡CCH(CH3)2 C) (CH3CH2)2C(CH3)C≡CCH2CH3 D) CH3CH2C(CH3)2C≡CC(CH3)3 E) (CH3CH2CH2)CH(CH3)C≡CC(CH3)3 Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Hard 33. What is the correct IUPAC name for the molecule shown below?
Cl
A) (R,Z)-4-chlorohept-5-en-2-yne B) (S,E)-4-chlorohept-5-en-2-yne C) (S,E)-4-chlorohept-2-en-5-yne D) (R,E)-4-chlorohept-5-en-2-yne E) (R,E)-4-chlorohept-2-en-5-yne Ans: E
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Hard 34. What is the correct IUPAC name for diisobutylacetylene?
A) Diisopropylbutyne B) 2,7-Dimethyl-4-octyne C) 3,6-Dimethyl-4-octyne D) 2,5-Diethyl-3-hexyne E) 2,2,5,5-Tetramethyl-3-hexyne Ans: B
Topic: Nomenclature of Alkynes Section: 10.2 Difficulty Level: Hard 35. What is the correct systematic IUPAC name for di-sec-butylacetylene?
A) 2-Ethyl-5-methyl-3-heptyne B) 2,7-Dimethyl-4-octyne C) 3,6-Dimethyl-4-octyne D) 2,5-Diethyl-3-hexyne E) 2,2,5,5-Tetramethyl-3-hexyne Ans: C
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Easy 36. Rank the following carbanions, with the weakest base first, then by increasing base
strength.
HC C CH3CH2
I II III
H2C CH
A) I < II < III B) II < III < I C) III < II < I D) III < I < II E) II < I < III Ans: A
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: 37. Rank the following bases, with the strongest base first, then by decreasing basicity.
HC C CH3CH2O H2NCH3CH2 H2C CH
I II III IV V A) III > I > V > II > IV B) III > V > IV > I> II C) V > I > III > II > IV D) III > IV > II > V > I E) IV > II > I > III > V Ans: B
Topic: Acidity of Acetylene and Terminal Alkynes
Section: 10.3 Difficulty Level: Easy 38. Rank the following acids, with the strongest acid first, then by decreasing acidity.
I II III IV V
H2O CH3CH3 NH3H2C HC CHCH2
A) V > I > IV > II > III B) III > IV > II > I > V C) V > I > III > II > IV D) I > IV > V > II > III E) IV > I > V > II > III Ans: D
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Easy 39. Which of the circled hydrogen atoms is the most acidic?
I II III IV V
H3C C C HH2C CH
HC HH
CH3H3C C H
CH3
CH3H3CC H
H
HH
A) I B) II C) III D) IV E) V Ans: E
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Easy 40. Sodium amide (NaNH2, sodamide) reacts with terminal alkynes in the role of the
A) Brønsted acid. B) Brønsted base. C) reducing agent. D) catalyst. E) electrophile. Ans: B
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Easy
41. Which of the bases below would quantitatively deprotonate a terminal alkyne? A) BuLi B) NH3 C) NaOH D) NaOCH2CH3 E) t-BuOK Ans: A
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Easy 42. Which of the bases below would result in the greatest deprotonation of the alkyne,
shown in the reaction below?
H3C C C H?
H3C C C A) NaOCH2CH3 (sodium ethoxide) B) t-BuONa (sodium tert-butoxide) C) NaH (sodium hydride) D) NaHCO3 (sodium bicarbonate) E) NaOH (sodium hydroxide) Ans: C
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Moderate 43. Which statement below best explains acetylene’s Ka being greater than ethylene’s?
A) Acetylide anions are resonance stabilized. B) The 4 π electrons of the acetylide anion better stabilize a negative charge. C) The electronegativity of sp carbons being greater than sp2 carbons. D) The electronegativity of sp carbons being less than sp2 carbons. E) Acetylene has only two hydrogen atoms while ethylene has four. Ans: C
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Moderate 44. Select the best explanation for why methanol, CH3OH, cannot be used as a solvent
for the deprotonation of a terminal alkyne by sodium amide, NaNH2. A) Sodium amide is not a strong enough base to deprotonate the alkyne. B) Sodium amide in methanol reduces alkynes to alkenes. C) Methanol is a poor solvent for dissolving alkynes.
D) Methanol is more acidic than the alkyne, and will be deprotonated instead. E) Methanol is toxic, and should be avoided when possible. Ans: D
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Moderate 45. What are the products of the reaction shown below?
CH3OH + CH3C≡C–Na+ → ? A) CH3C≡CCH3 + Na+OH– B) CH3C≡CH + CH3O–Na+ C) CH3C≡COCH3 + Na+OH– D) CH3OC≡CH + Na+CH3
– E) no reaction Ans: B
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Moderate 46. The major result of treating 1-butyne with 6M aqueous NaOH would be:
A) the production of the sodium acetylide. B) the production of an alkene. C) the production of an alkane. D) the production of an enol. E) nothing, as the alkyne would not react. Ans: E
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Hard 47. Which of the circled hydrogen atoms is the least acidic?
I II III IV V
H3C C C HH2C CH
HC HH
CH3H3C C H
CH3
CH3H3CC H
H
HH
A) I B) II C) III D) IV E) V
Ans: C Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Hard 48. Of the species listed below, select those less basic than acetylide?
A) BuLi B) NaNH2 C) NaOCH3 D) both A and C E) both B and C Ans: C
Topic: Preparation of Alkynes Section: 10.4 Difficulty Level: Easy 49. For the transformation shown below, select the expected major product.
Br
Br
xs NaNH2
NH3
I II III IV V
HC C CH2
NH2
H2N
A) I B) II C) III D) IV E) V Ans: D
Topic: Preparation of Alkynes Section: 10.4 Difficulty Level: Easy 50. For the reaction shown below, select the expected major product.
BrBr KOH
Δ?
BrBrO
Br
I II III IV V A) I B) II C) III D) IV E) V Ans: B
Topic: Preparation of Alkynes Section: 10.4 Difficulty Level: Moderate 51. For the reaction sequence below, select the expected major product.
1) Br2 2) 3 eq. NaNH2/NH3
3) H2O A) 3-methylhexane B) 1-bromo-3-methylhexene C) 2-bromo-3-methylhexene D) 3-methyl-1-hexyne E) 3-methyl-2-hexyne Ans: D
Topic: Preparation of Alkynes Section: 10.4 Difficulty Level: Hard 52. Treatment of 2,2-dibromobutane with molten KOH at 200°C would be expected to
produce which of the following: A) (E)-2-bromo-2-butene B) (Z)-2-bromo-2-butyne C) 1,2-butadiene D) 1-butyne E) 2-butyne Ans: D
Topic: Acidity of Acetylene and Terminal Alkynes Section: 10.3 Difficulty Level: Hard 53. When preparing terminal alkynes by an elimination reaction, sodium amide
(NaNH2) dissolved in liquid ammonia (NH3) is used most frequently. Which of the following statements offers the best explanation for the above statement?
A) The above statement is false; terminal alkynes are not produced under the given conditions.
B) Sodium amide deprotonates the terminal alkyne, driving formation of the alkynide ion.
C) Only sodium amide is a strong enough base to deprotonate a carbon. D) Terminal alkynes are more stable than the internal alkynes, and are always
the favored product. E) Steric hindrance favors preparation of the less substituted terminal alkyne. Ans: B
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 54. For the reaction shown, select the expected major organic product.
I II III IV V
?H2Pt
A) I B) II C) III D) IV E) V Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 55. For the reaction shown, select the expected major organic product.
Na/NH3
I II III IV V
?
A) I B) II C) III D) IV E) V Ans: B
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 56. For the reaction shown, select the expected major organic product.
I II III IV V
?H2
Lindlar's cat.
A) I B) II C) III D) IV E) V Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 57. Reduction of 1 mole of (3E,5Z)-3-methylhepta-3,5-dien-1-yne will require how
many moles of hydrogen (H2)? A) 1 B) 2
C) 3 D) 4 E) 5 Ans: D
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 58. Select the reagent(s) expected to accomplish the transformation shown below.
C CCH3CH2 CH2CH3? CH3CH2CH2CH2CH3
A) H2, Ni B) H2, Ni2B C) Na, NH3(l) D) A and B E) B and C Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 59. Select the best reagent expected to convert 3-heptyne to cis-3-heptene.
A) NaNH2, NH3 B) Na, NH3 C) H2, Lindlar’s catalyst D) Both A and C E) Both B and C Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 60. Which of the reagents below would convert 2-pentyne to trans-2-pentene?
A) NaNH2, NH3 B) Na, NH3 C) H2, Lindlar’s catalyst D) H2, Pd/C E) H2O, HgSO4/H2SO4 Ans: B
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 61. Select the best reagent to convert 3-heptyne to trans-3-heptene?
A) Na/NH3 B) 1 eq. NaNH2, NH3 C) xs NaNH2, NH3 D) H2/Pt E) H2/Lindlar's catalyst Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 62. Select the reagent(s) expected to accomplish the transformation shown below.
CCH3CH2C
CH2CH3C CCH3CH2 CH2CH3
?
H
H
A) H2, Pd B) H2, Lindlar’s catalyst C) Na, NH3(l) D) A and B E) B and C Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 63. Reaction of 3,4,5-trimethyl-4-hexen-1-yne with H2 and Pd/C will produce which of
the following compounds? A) 2,3,4-Trimethylhexane B) 3,4,5-Trimethylhexane C) 2,3,4-Trimethyl-1-hexene D) 3,4,5-Trimethyl-1-hexyne E) 2,3,4-Trimethyl-5-hexyne2 Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 64. Reaction of (3E,5Z)-3-methylhepta-3,5-dien-1-yne with H2 and Pd/C will produce
which of the compounds below? A) 1-sec-Butylbutane B) 2-Butylbutane2 C) 3-Methylheptane D) 3-Methyl-1-heptyne E) (3E,5Z)-3-Bethyl-1,3,5-heptatriene Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 65. Of the reaction conditions provided below, which would be expected to convert 1
mole of 4-methyl-1-pentyne into 2-methylpentane? A) H2, Lindlar’s catalyst B) Na, NH3(l) C) 2 moles of HCl D) 2 moles H2, Pt E) 1 mole H2, Pt Ans: D
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 66. Which reagents shown below would be expected to convert 2-pentyne to (Z)-2-
pentene? A) H2, Pt B) Na, NH3 C) H2, Lindlar's catalyst D) Xs HCl E) HgSO4, H2O Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 67. For the reaction shown below, what is the IUPAC name of the expected product?
?Na
NH3(l) A) 2-methylhexane B) (Z)-2-methyl-4-hexene C) (E)-2-methyl-4-hexene D) (Z)-5-methyl-2-hexene E) (E)-5-methyl-2-hexene Ans: E
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 68. Select the reagent(s) expected to accomplish the transformation shown below.
C CCH2CH3H3CH2C
C CCH3CH2 CH2CH3? H H
A) H2, Ni B) H2, Ni2B C) H2, Lindlar’s catalyst D) A and B E) B and C Ans: E
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 69. What is the expected major organic product from treatment of 4-methyl-2-pentyne
with excess hydrogen in the presence of a platinum catalyst? A) (E)-4-methyl-2-pentene B) (Z)-4-methyl-2-pentene C) 2-methylpentane D) 4-methylpentane E) Equal mixture of A and B Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 70. What is the expected major organic product from treatment of 4-methyl-2-pentyne
with hydrogen in the presence of Lindlar's catalyst? A) (E)-4-methyl-2-pentene B) (Z)-4-methyl-2-pentene C) (E)-2-methyl-2-pentene D) (Z)-2-methyl-2-pentene E) 2-methylpentane Ans: B
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 71. What is the expected major organic product from treatment of 4-methyl-2-pentyne
with sodium metal in liquid ammonia? A) (E)-4-methyl-2-pentene B) (Z)-4-methyl-2-pentene C) (E)-2-methyl-2-pentene D) (Z)-2-methyl-2-pentene E) 2-methylpentane Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 72. In the reaction between an alkyne and Na metal in liquid ammonia, Na’s role is as
the: A) Brønsted acid. B) Brønsted base. C) reducing agent. D) catalyst. E) electrophile. Ans: C
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Modertate 73. In a dissolving metal reduction of an alkyne, a postulated intermediate is the trans
alkenyl radical, shown below. In which orbital type would the unpaired electron be located?
R
H R
A) sp B) sp2 C) sp3 D) p E) s Ans: B
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 74. For the reaction shown below, the resulting stereochemistry of the expected
product is best described as: H2Pt
A) only (S) B) only (R) C) racemic D) meso E) achiral Ans: E
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Moderate 75. Complete hydrogenation of a mixture of 1-octyne, 2-octyne, and 3-octyne, in the
presence of a palladium catalyst, would produce how many distinct eight-carbon hydrocarbon products?
A) 1 B) 2 C) 3 D) 6 E) 8 Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Hard 76. For the reaction shown below, the resulting stereochemistry of the expected
product is best described as: H2
Ni2B (P-2) A) (R,E) B) (S,E) C) (R,Z) D) (S,Z) E) only (S) Ans: D
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Easy 77. Which of the compounds shown below would be the most likely product expected
from the reaction scheme shown?
xs HCl ?
Cl
CH3CH2C CH
Cl Cl ClCl
I II III IV V
Cl
Cl
Cl
A) I B) II C) III D) IV E) V Ans: C
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Easy 78. The expected major product from treatment of 1-pentyne with excess HBr in the
presence of peroxides is: A) 1-bromo-1-pentene B) 2-bromo-1-pentene C) 1,1-dibromopentane
D) 2,2-dibromopentane E) 1,2-dibromopentane Ans: C
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Easy 79. The expected major product from the treatment of 1-pentyne with 1 equivalent of
HBr is: A) 1-bromo-1-pentene B) 2-bromo-1-pentene C) 1,1-dibromopentane D) 2,2-dibromopentane E) 1,2-dibromopentane Ans: B
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Easy 80. The expected major product from the treatment of 1-pentyne with 2 equivalents of
HBr is: A) 1-bromo-1-pentene B) 2-bromo-1-pentene C) 1,1-dibromopentane D) 2,2-dibromopentane E) 1,2-dibromopentane Ans: D
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Easy 81. For the reaction below, select the structure of the expected major organic product.
1 eq HCl?
I II III IV V
Cl
Cl
Cl Cl
Cl
A) I B) II C) III D) IV E) V Ans: C
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Moderate 82. What is the major expected product(s) of the reaction shown below?
C CCH3CH2 CH3HCl
? A) 2,2-Dichloropentane B) 3,3-Dichloropentane C) 2,3-Dichloropentane D) A and B E) B and C Ans: D
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Moderate 83. For the reaction shown, select the expected major organic product.
1) 1 eq HCl
2) 1 eq HBr?
I II III IV V
BrCl
ClBr
BrCl Br
Cl
Br
Cl
Cl
Br
A) I B) II C) III D) IV E) V Ans: D
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Moderate 84. Which of the compounds shown below would be the most likely product expected
from the reaction scheme shown? HBr
ROOR?(CH3)2CHCH2C CH
Br
Br
Br
BrBr Br
I II III IV A) I and II B) III and IV C) II and III D) II and IV E) I and IV Ans: E
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Moderate 85. Select the expected major product(s) from the treatment of 1-pentyne with
1 equivalent of HBr in the presence of peroxides. A) 2-Bromo-1-pentene B) (E)-1-Bromo-1-pentene C) (Z)-1-Bromo-1-pentene D) A and B E) B and C Ans: E
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Moderate 86. What mechanistic intermediate is used to explain the preference for addition of the
Br atom, of HBr, to the internal carbon of a terminal alkyne? A) Formation of a more stable primary vinylic carbocation. B) Formation of a more stable secondary vinylic carbocation. C) Addition of the H atom to the carbon already with an H. D) Addition of H, from HBr, to the least hindered carbon. E) Steric hindrance for the approach of the Br atom to the primary carbon. Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 87. For the transformation shown, select the most appropriate reagent(s) to effect the
change. ?
(CH3)2CHCH2CCH3O
(CH3)2CHCH2C CH
A) H2SO4, HgSO4 B) 1. Disiamylborane, 2. HO–, H2O, H2O2 C) K2Cr2O7, H+ D) NaOCl E) H2, Pd Ans: A
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 88. For the transformation shown, select the most appropriate reagent(s) to effect the
change. ?
(CH3)2CHCH2CH2CH(CH3)2CHCH2C CHO
A) H2SO4, HgSO4 B) 1. Disiamylborane, 2. HO–, H2O, H2O2 C) K2Cr2O7, H+ D) NaOCl E) H2, Pd Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 89. For the reaction shown, which of the compounds below would be the expected
major, and final, organic product?
CH3CH2CH(CH3)C CH HgSO4?+ H2O
H2SO4
I II III IV V
OOOH
O OH
A) I B) II C) III D) IV E) V Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 90. For the reaction shown, which of the compounds listed would be the expected
major, and final, organic product?
H2O, H2SO4HgSO4
?
I II III IV V
O
O
O
OH
OH
A) I B) II C) III D) IV E) V Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 91. For the reaction shown, which of the compounds below would be the expected
major organic product?
H2O, H2SO4HgSO4
OH OH
OH
O O
O
HO OH
I II III IV V
?
A) I B) II C) III D) IV E) V Ans: C
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 92. For the reaction shown, which of the compounds below would be the expected
major, and final, organic product?
?
I II III IV V
O
O
O
OH
OH
1) BH3•THF
2) H2O2, NaOH
A) I B) II C) III D) IV E) V Ans: C
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 93. For the reaction shown, which of the compounds below would be the expected
major, and final, organic product?
OH
I II III IV V
?
OOH OOH
OH
1) BH3•THF
2) H2O2, NaOH
A) I
B) II C) III D) IV E) V Ans: C
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 94. For the reaction shown, which of the compounds listed would be the expected
major, and final, organic product?
?
I II III IV V
1) Disiamylborane
2) H2O2, NaOH
OO
OH
OH OHOH
A) I B) II C) III D) IV E) V Ans: E
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Easy 95. For the reaction shown, which of the compounds listed would be the expected
major, and final, organic product?
CH3CH2C(CH3)2C CH
I II III IV V
OO OHO OH
?1) Disiamylborane
2) H2O2, NaOH
A) I
B) II C) III D) IV E) V Ans: C
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 96. For the reaction shown, which of the compounds listed would be the expected enol
intermediate?
H2O, H2SO4
HgSO4
OH
I II III IV V
?
OH OOH OHOH
OH
A) I B) II C) III D) IV E) V Ans: A
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 97. For the reaction shown, which of the compounds below would be the expected enol
intermediate?
OH
I II III IV V
OH OOH OH OH
OH
?1) BH3•THF
2) H2O2, NaOH
A) I
B) II C) III D) IV E) V Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 98. Which of the ketones below could not be prepared by an acid-catalyzed hydration
of an alkyne? O OOO O
I II III IV V A) I B) II C) III D) IV E) V Ans: D
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 99. Consider the list of alkyne addition reactions below, and select all those that
involve an enol intermediate. A) Hydroboration/oxidation B) HgSO4 catalyzed hydration in dilute H2SO4 C) Hydrohalogenation D) Both A and B E) Both A and C Ans: D
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 100. In an acid-catalyzed hydration, which of the following alkynes is expected to
produce a single ketone? A) 2-decyne B) 3-decyne
C) 4-decyne D) 5-decyne E) All of the above will give a single product Ans: D
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 101. In an acid-catalyzed hydration, which of the following alkynes gives a single
ketone? A) 2-pentyne B) 2-hexyne C) 2-heptyne D) 3-hexyne E) 3-heptyne Ans: D
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 102. For the reaction below, how many different organic products would be expected?
H2O, H2SO4
HgSO4?
A) one B) two C) three D) four E) five Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 103. Which of the following alkynes would give a single product under hydroboration-
oxidation conditions? A) 1-hexyne B) 2-hexyne C) 3-hexyne D) A and B would each give a single product
E) A and C would each give a single product Ans: E
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 104. Which of the alkynes below, after undergoing an acid-catalyzed hydration, would
be expected to produce two different ketones in nearly equivalent yields? A) 1-hexyne B) 2-hexyne C) 3-hexyne D) 3-methyl-1-pentyne E) 4-methyl-1-pentyne Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 105. For the reaction shown, which of the compounds listed below would be the
expected major, and final, organic product?
?
I II III IV V
1) 9-BBN
2) H2O2, NaOH
O O
OH
OHOHOH
A) I B) II C) III D) IV E) V Ans: D
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 106. For the reaction below, which of the alkynes listed would be expected to produce
the product under the conditions shown?
I II III IV V
1) 9-BBN
2) H2O2, NaOH? O
A) I B) II C) III D) IV E) V Ans: C
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 107. What functional group would be expected to be found in the major, and final,
organic product upon completion of the reaction between 1-hexyne and a mixture of mercuric sulfate and aqueous sulfuric acid?
A) aldehyde B) ketone C) diol D) ether E) carboxylic acid Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 108. What functional group would be expected to be found in the major, and final,
organic product upon completion of the reaction below.
?1) 9-BBN
2) H2O2, NaOH
A) aldehyde B) ketone C) diol D) enol E) alkene
Ans: A Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 109. What is the expected functional group produced when cyclooctyne is reacted with
disiamylborane, followed with treatment of basic hydrogen peroxide? A) aldehyde B) ketone C) diol D) ether E) carboxylic acid Ans: B
Topic: Hydration of Alkynes Section: 10.7 Difficulty Level: Moderate 110. Which of the reagents below, upon completion of reaction with a terminal alkyne,
would be expected to produce an aldehyde as the final major organic product? 1) Disiamylborane
2) H2O2, NaOH
1) 9-BBN
2) H2O2, NaOH1) BH3•THF
2) H2O2, NaOH
H2O, H2SO4HgSO4
I II III IV A) I and II B) II and III C) III and IV D) I, II and IV E) I, III and IV Ans: E
Topic: Halogenation of Alkynes Section: 10.8 Difficulty Level: Easy 111. What is the major product of the reaction shown below?
C CCH3CH2CH2 CH3excess Cl2
?CCl4
A) (E)-2,3-Dichloro-2-hexene B) (Z)-2,3-Dichloro-2-hexene C) 2,2-Dichlorohexane D) 3,3-Dichlorohexane E) 2,2,3,3-Tetrachlorohexane
Ans: E Topic: Halogenation of Alkynes Section: 10.8 Difficulty Level: Easy 112. Which of the compounds shown below would be the most likely product expected
from the reaction scheme shown?
xs Cl2 ?
Cl
CH3CH2C CH
Cl Cl ClCl
I II III IV V
Cl
Cl
Cl
Cl
Cl Cl
Cl
A) I B) II C) III D) IV E) V Ans: E
Topic: Halogenation of Alkynes Section: 10.8 Difficulty Level: Easy 113. Careful addition of 1 equivalent of Br2 to the alkyne shown below would be
expected to produce which of the following as the major organic product?
1 eq Br2?
I II III IV V
BrBr
BrH
Br
BrBr
Br
CCl4
H Br
Br BrBr Br
A) I B) II C) III D) IV E) V Ans: B
Topic: Halogenation of Alkynes Section: 10.8 Difficulty Level: Easy 114. Which of the compounds shown below would be the most likely product expected
from the reaction scheme shown?
?(CH3)2CHCH(CH3)C
Br
BrBrBr
I II III IV V
CHexcess Br2
CCl4
BrBr BrBrBr
Br
Br
Br
A) I B) II C) III D) IV E) V Ans: A
Topic: Halogenation of Alkynes (Hydrohalogenation…) Section: 10.8 Difficulty Level: Easy 115. The expected major product from treatment of 1-pentyne with excess HBr is:
A) 1,1-dibromo-1-pentene B) 1,2-dibromo-1-pentene C) 1,1-dibromopentane D) 2,2-dibromopentane E) 1,1,2,2-tetrabromopentane Ans: D
Topic: Halogenation of Alkynes Section: 10.8 Difficulty Level: Easy 116. For the reaction below, select the structure of the major organic product.
xs Br2 ?
I II III IV V
Br
Br Br
Br
BrBr
BrBr
Br
BrBr Br
Br
A) I B) II C) III D) IV E) V Ans: D
Topic: Halogenation of Alkynes Section: 10.8 Difficulty Level: Moderate 117. Select the expected major product(s) from the treatment of 1-pentyne with
1 equivalent of Br2. A) 1,1-dibromo-1-pentene B) (E)-1,2-dibromo-1-pentene C) (Z)-1-bromo-1-pentene D) A and B E) B and C Ans: B
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Easy 118. Which of the following conditions effectively cleaves a carbon-carbon triple bond?
A) HgSO4 and aqueous H2SO4 B) 1) Disiamylborane 2) H2O2, NaOH C) H2, Lindlar’s catalyst D) 1) O3 2) H2O E) Na, NH3(l) Ans: D
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Easy
119. Predict the major organic products of the reaction below.
1) O3
2) H2O
O
OH O
HOC O
OO
OH
?
I II III IV A) I and II B) II an III C) I and IV D) II and III E) 1 and III Ans: C
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Easy 120. For the reaction sequence shown, what are the expected major organic products?
1. O3
2. H2O
I II III IV V
O
H
O O
OH
O
++ + + +
OC OHH3C
C OOH3C
O
OH HO
O
OH
?
OH O
C OO
H
A) I B) II C) III D) IV E) V Ans: B
Topic: Ozonolysis of Alkynes
Section: 10.9 Difficulty Level: Easy 121. What are the expected major products of the reaction sequence shown below?
1. O3
2. H2O?
I II III IV V
O
OH
O
HOO C OO O
A) I and II B) I, III, and V C) II, III, and IV D) I and IV E) II, III, IV Ans: D
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Easy 122. What is the expected major product of the reaction sequence shown below?
I II III IV V
1. O3
2. H2O?
O
OCO2HCO2H
CO2HOO
O
O
A) I B) II C) III D) IV E) V Ans: B
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Easy 123. Ozonolysis of one mole of the compound shown is expected to produce how many
moles of CO2 upon completion of the reaction?
A) 1 B) 2 C) 3 D) 4 E) 8 Ans: C
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Moderate 124. Select the alkyne listed below that, upon treatment with ozone followed by water,
would not produce carbon dioxide and a carboxylic acid as the final products? A) Ethyne B) Propyne C) 1-Butyne D) 1-Pentyne E) 1-Hexyne Ans: A
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Moderate 125. Which of the following alkynes, upon ozonolysis, would be expected to produce
only one major organic product? A) 1-Hexyne B) 2-Hexyne C) 3-Hexyne D) 2-Heptyne E) 3-Heptyne Ans: C
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Hard
126. Provide the IUPAC name for the alkyne expected to produce the two compounds listed below upon ozonolysis? CH3CH2CO2H and (CH3)3CCO2H
A) 1-tert-butyl-1-butyne B) 2,2-dimethyl-3-hexyne C) 3,3-dimethyl-2-hexyne D) 5,5-dimethyl-3-hexyne E) 3-octyne Ans: B
Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Hard 127. Which alkyne would produce the products below upon ozonolysis?
OH
OC OO
1. O3
2. H2O? HO
OOH
O+ +
A) HC≡CC≡CCH2C≡CH B) HC≡CCH2CHCH2C≡CH C) CH3C≡CCH2C≡CCH3 D) HC≡CCH2CH2C≡CCH3 E) CH3C≡CC≡CC≡CH Ans: D
Topic: Alkylation of Terminal Alkynes Section: 10.10 Difficulty Level: Easy 128. What is the IUPAC name for the expected product of the transformation below?
1) NaNH2
2) CH3CH2CH2Br
H
H3C
A) Propyne B) 1-Hexyne C) 2-Hexyne D) 3-Hexyne E) (E)-3-Hexyne Ans: C
Topic: Alkylation of Terminal Alkynes Section: 10.10
Difficulty Level: Easy 129. What is the IUPAC name for the expected final product of the transformation
below?
1) NaNH2
2) CH3CH2CH2CH2Br
H
H
3) NaNH2
4) CH3CH2Br?
A) 5-Decyne B) 3-Hexyne C) 1-Octyne D) 3-Octyne E) 5-Octyne Ans: D
Topic: Alkylation of Terminal Alkynes Section: 10.10 Difficulty Level: Easy 130. What is the expected major final product of the reaction sequence shown below?
1) NaNH2C
CH
H
3) NaNH2
4) CH3Br2)Br
CC
?
I II III IV V
CC C C
C CC C
A) I B) II C) III D) IV E) V Ans: B
Topic: Alkylation of Terminal Alkynes Section: 10.10 Difficulty Level: Easy 131. What is the expected major final product of the reaction sequence shown below?
1) NaNH2C
CH
H
3) NaNH2
4)2)
CC
?
I II III IV
CCC C
C C
BrBr
A) I B) II C) III D) IV E) None of the shown products will be produced. Ans: D
Topic: Alkylation of Terminal Alkynes Section: 10.10 Difficulty Level: Moderate 132. What is the expected major product of the reaction sequence shown below?
HC≡C:– + (CH3)2CHCH2Br → ? A) CH≡CH + (CH3)2CHC≡CH B) (CH3)2CHC≡CCH3 C) (CH3)2CHCH2C≡CH D) (CH3)2CHCHBrC≡CH E) CH3CHCH2C≡CCH3 Ans: C
Topic: Alkylation of Terminal Alkynes Section: 10.10 Difficulty Level: Moderate 133. Which of the alkyl bromides listed would work as a reagent in step 2 of the reaction
sequence shown, with the resulting major product being an internal alkyne?
Br
BrBr
BrBr
I II III IV V
1) NaNH2
2) R–Br
R
A) I and III B) II and IV C) III, IV, V D) I, II, IV E) II, III, V Ans: D
Topic: Alkylation of Terminal Alkynes Section: 10.10 Difficulty Level: Hard 134. Why would the following reaction sequence not produce the expected product
shown?
1) NaNH2C C H
H
3) NaNH2
4) CH3Br2) Br
C C
(NOT produced)
A) NaNH2 is used in the reduction of alkynes to trans alkenes. B) The secondary alkylhalide would undergo an elimination reaction. C) Br is not a good enough leaving group. D) The terminal alkyne is not acidic enough to be deprotonated. E) The reaction sequence is correct and will produce the shown product. Ans: B
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Easy 135. What is the final major product expected for the following reaction sequence?
H
H3C
1) NaNH22) (CH3)2CHCH2Br3) Na, NH3(l)
?
I II III IV V A) I B) II C) III D) IV E) V Ans: A
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Easy 136. Which of the compounds listed would be a final major product for the following
reaction sequence?
Br 1) 2 NaNH2
NH3Br
I II III IV V
Br
2) HBrROOR
?
Br
BrBr
Br
A) I B) II C) III D) IV E) V Ans: C
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Easy 137. Which of the following methods would be expected to efficiently produce cis-2-
butene? A) CH3CHBrCH2CH3 + (CH3)3COK/(CH3)3COH B) CH3C≡CCH3 + H2, Pt C) CH3C≡CCH3 + H2, Ni2B (P-2) D) CH3C≡CCH3 + Na, NH3(l) E) CH3CHBrCH2CH3 + NaNH2 Ans: C
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Easy 138. Which sequence of reagents would be expected to accomplish the transformation
shown?
?
A) 1) HBr; 2) 2 NaNH2 B) 1) Br2; 2) 2 NaNH2 C) 1) Br2, H2O; 2) NaNH2 D) 1) HBr/ROOR; 2) excess NaNH2 E) 1) Na, NH3(l) Ans: B
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Moderate 139. Which sequence of reagents would be expected to accomplish the transformation of
1-butyne shown below?
HC C CH2CH3? HO
A) 1) H2O/H2SO4, HgSO4 cat.; 2) H2, Pt B) 1) HBr; 2) H2, Pt; 3) NaOH C) 1) H2, Lindlar catalyst; 2) BH3•THF; 3) H2O2, NaOH D) 1) HBr, peroxides; 2) NaOH; 3) H2, Pt E) 1) O3 2) H2O Ans: C
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Moderate 140. Which sequence of reactions is expected to produce cis-3-octene as the final, and
major, organic product?
1) propyne, NaNH22) 1-bromopentane3) aqueous H2SO4, cat. HgSO4
1) 1-butyne, NaNH22) 1-bromobutane3) H2, Lindlar's cat.
I II III
IV V
1) propyne, NaNH22) 1-bromopentane3) H2, Ni2B (P-2)
1) 1-butyne, NaNH22) 1-bromobutane3) Na, NH3(l)
1) 1-butyne, NaNH22) 1-bromobutane3) H2, Pd/C
A) I B) II C) III D) IV E) V Ans: B
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Hard 141. Which sequence of reactions is expected to produce the product below as the final,
and major, organic product?
D OHHO
D
H
H? + enantiomer
A) 1) H2, Lindlar’s cat.; 2) OsO4; 3) NaHSO3/H2O B) 1) H2, Pt; 2) OsO4; 3) NaHSO3/H2O C) 1) OsO4; 2) NaHSO3/H2O; 3) H2, Lindlar’s cat. D) 1) Na, NH3(l); 2) OsO4; 3) NaHSO3/H2O E) 1) OsO4; 2)NaHSO3/H2O; 3) Na, NH3(l) Ans: A
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Hard 142. Which sequence of reactions is expected to produce the product below as the final,
and major, organic product?
CH3OH
HO
H
H
CH3
? + enantiomer
A) 1) Na, NH3(l); 2) OsO4; 3) NaHSO3/H2O B) 1) H2, Lindlar’s cat.; 2) MCPBA; 3) H3O+ C) 1) H2, Ni2B (P-2); 2) KMnO4, NaOH (cold) D) Both A and B E) Both A and C Ans: D
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Hard 143. Which sequence of reactions is expected to produce the product below as the final,
and major, organic product?
CH2CH3Br
Br
H
H? + enantiomer
A) 1) Br2; 2) H2, Lindlar’s cat. B) 1) H2, Lindlar’s cat.; 2) Br2 C) 1) Br2; 2) Na, NH3(l) D) 1) Na, NH3(l); 2) Br2 E) 1) Br2, 2) H2, Pt Ans: B
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Hard 144. What is the final major product expected for the following reaction sequence?
1) H2, Ni2B (P-2) 2) Cl2
A) (R)-3-Chlorohexane B) (S)-3-Chlorohexane C) meso-3,4-Dichlorohexane D) Racemic (2R,3R) and (2S,3S)-3,4-dichlorohexane E) 2,3-Dichloro-3-hexene
Ans: D Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Hard 145. What is the final major product expected for the following reaction sequence?
1) Na, NH3(l) 2) Br2
A) (R)-3-Bromohexane B) (S)-3-Bromohexane C) meso-3,4-Dibromohexane D) Racemic (2R,3R) and (2S,3S)-3,4-dibromohexane E) 2,3-Dibromo-3-hexene Ans: C
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Hard 146. Which sequence of reactions is expected to produce the product below as the final,
and major, organic product?
1) , NaNH22) (CH3)2CHCH2Br3) aqueous H2SO4, cat. HgSO4
1) , NaNH22) (CH3)2CHBr3) Disiamylborane4) H2O2, NaOH
I II III
IV V
1) (CH3)2CHBr, NaNH22) 3) O34) H2O
1) , NaNH22) (CH3)2CHCH2Br3) BH3•THF4) H2O2, NaOH
1) (CH3)2CHCH2Br, NaNH22)3) 9-BBN4) H2O2, NaOH
O?
HC CH CH3C CH
CH3C CHHC CH
CH3C CH
A) I B) II C) III D) IV E) V Ans: A
Topic: Alkyne Nomenclature Section: 10.2 Difficulty Level: Easy 147. Determine the possible number of alkynes with molecular formula C5H8.
A) one B) two C) three D) four E) five Ans: C
Topic: Alkyne Nomenclature Section: 10.2 Difficulty Level: Easy 148. Provide the systematic IUPAC name for CH3CH(CH3)C(CH3)2C≡CCH(CH3)2. Ans: 2,5,5,6-Tetramethyl-3-heptyne Topic: Alkyne Nomenclature Section: 10.2 Difficulty Level: Easy 149. Provide the systematic IUPAC name for CH3C≡CC(CH3)2CH(CH2CH3)2.
Ans: 5-Ethyl-4,4-dimethyl-2-heptyne Topic: Alkyne Nomenclature Section: 10.2 Difficulty Level: Easy 150. Provide the systematic IUPAC name for CH3CHBrC≡C(CH2)3CH3.
Ans: 2-Bromo-3-octyne
Topic: Alkyne Nomenclature Section: 10.2 Difficulty Level: Easy 151. Provide the systematic IUPAC name for the following compound:
Ans: 4-sec-butyl-2-octyne Topic: Alkyne Nomenclature Section: 10.2 Difficulty Level: Easy 152. Draw the line-bond structure for the compound with the IUPAC name: 2,5,9-
Trimethyl-2-decen-7-yne.
Ans: Topic: Acidity of Terminal Alkynes Section: 10.3 Difficulty Level: Easy 153. Rank the following hydrocarbons in order of decreasing acidity (most acidic to
least acidic).
I II III A) I > II > III B) I > III > II C) II > III > I D) II > I > III E) III > I > II F) III > II > I
Ans: F Topic: Preparation of Alkynes Section: 10.4 Difficulty Level: Easy 154. Describe a sequence of reactions by which 2-hexyne can be straightforwardly
prepared from acetylene.
Ans: 1) NaNH2 2) CH3Br 3) NaNH2 4) CH3CH2CH2Br
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 155. Determine the reagent(s) required to prepare trans-2-heptene from 2-heptyne?
A) H2, Pt B) Na, NH3(l) C) H2, Ni2B D) NaOEt E) H2SO4, H2O
Ans: B Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 156. Provide the reagent(s) expected to accomplish the transformation shown below:
C C CH2CH3H3CH2C CH3(CH2)4CH3?
A) H2, Pt B) Na, NH3(l) C) H2, Ni2B D) NaOEt E) H2SO4, H2O
Ans: A
Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 157. Provide the reagent(s) expected to accomplish the transformation shown below:
C CCH2CH3
C CCH3CH2 CH2CH3?
H3CH2C
HH
A) H2, Pt B) Na, NH3(l) C) H2, Ni2B D) NaOEt E) H2SO4, H2O
Ans: C Topic: Reduction of Alkynes Section: 10.5 Difficulty Level: Easy 158. Determine which compound will react with sodium in liquid ammonia to form
trans-3-hexene. A) cis-3-hexene B) trans-2-hexene C) 3-hexyne D) 2-hexyne E) cis-2-hexene Ans: C
Topic: Hydrohalogenation of Alkynes Section: 10.6 Difficulty Level: Moderate 159. Provide the structure(s) of the expected major organic product(s) from the
following reaction: HBr
ROOR(CH3)2CHCH2C CH
Ans: Br and Br Topic: Hydration of Alkynes
Section: 10.7 Difficulty Level: Easy 160. Provide the structure(s) of the expected major organic product from the following
reaction:
CH3CH2C(CH3)2C CH1) Disiamylborane
2) H2O2, NaOH
Ans: O Topic: Ozonolysis of Alkynes Section: 10.9 Difficulty Level: Easy 161. Provide the structure(s) of the expected major organic product(s) from the
following reaction:
1) O3
2) H2O
Ans:
O
OH and O
HO
Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Easy 162. Provide the structure(s) of the expected major organic product from the following
reaction sequence:
Br
1) NaNH2
2)
3) H2
Lindlar's cat.
Ans: Topic: Synthetic Strategies Section: 10.11 Difficulty Level: Moderate
163. Which of the following best explains why the synthetic route shown below would be unsuccessful?
1) CH3CH2Br2) NaNH2
3) (CH3)3CBr
HC C CH3CH2C CC(CH3)3
A) The alkynide anion is not a strong enough nucleophile to react with 1-
bromopropane in step 1. B) Sodium amide is not a strong enough base to deprotonate the terminal alkyne
in step 2. C) The alkynide anion formed by reaction with sodium amide will facilitate an
E2 (rather than SN2) reaction with t-butyl bromide. D) Both substitution reactions will occur on the same end of the alkyne, making a
product different than the one shown. E) Reaction with sodium amide will result in formation of a primary alkyne. Ans: C