1. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved. Chapter 10 Alkynes Organic Chemistry Second Edition David Klein

2. Please note: If your clicker system can only hold 5 multiple choice answers, we have provided ‘alternate answers’ for those questions in which the author originally had more than 5 choices. These answers appear on the slides with a green background. If your clicker system can hold more than 5 multiple choice answers, please delete the slides with the green backgrounds, and use the original answers the author has listed. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

3. a. 3,9-dimethyl-3-decyne b. 3,9-dimethyl-7-decyne c. 2,8-dimethyl-7-decyne d. 2,8-dimethyl-3-decyne Section: 10.2 1. What is the correct IUPAC name for the following structure? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

4. Answer: d. For more examples of this type of problem, see SkillBuilder 10.1. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

5. Section: 10.3 2. Which bases are strong enough to deprotonate the following compound efficiently? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

6. Answer: A, D, E. For more examples of this type of problem, see SkillBuilder 10.2. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

7. Alternate Answers: Section: 10.3 2. Which bases are strong enough to deprotonate the following compound efficiently? A. A, B, C B. A, B, D C. A, B, E D. A, D, E E. A, D, F Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

8. Answer: d. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

9. Section: 10.3 3. Which of the following reactions will not occur to an appreciable extent? a.1 b.2 c.3 d.4 e.2 and 4 Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

10. Answer: e. For more examples of this type of problem, see SkillBuilder 10.2. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

11. Section: 10.4 4. Which of the following structures will form alkynes upon treatment with excess NaNH 2 followed by H 2 O? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

12. Answer: A. B, C, D, F. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

13. Alternate Answer: Section: 10.4 4. Which of the following structures will form alkynes upon treatment with excess NaNH 2 followed by H 2 O? A. A, B, C, D, E, F B. A, B, C, D, E C. A, B, C, D, F D. A, B, D, E, F E. A, C, D, E, F Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

14. Answer: c. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

15. a. H 2 /Lindlar's Catalyst b. Na in NH 3 (l) c. H 2 /Pt d. H 2 /Ni 2 B e. a and d Section: 10.5 5. What reagent is needed for the following reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

16. Answer: c. The product is a fully hydrogenated alkyne, and any of the strong reducing agents like Pt, Pd, and Ni in the presence of H 2 will fully reduce an alkyne. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

17. a. H 2 /Lindlar's Catalyst b. Na in NH 3 (l) c. H 2 /Pt d. H 2 /Ni 2 B e. a and d f. none of the above Section: 10.5 6. What reagent is needed for the following reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

18. Answer: b. The product is a trans double bond.1) Na in NH 3 2) NH 4 Cl is the only way to turn an alkyne into a trans double bond. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

19. a. H 2 /Lindlar's Catalyst b. Na in NH 3 (l) c. H 2 /Pt d. H 2 /Ni 2 B e. a and d Alternate Answer: Section: 10.5 6. What reagent is needed for the following reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

20. Answer: b. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

21. Section: 10.5 7. What reagent is needed for the following reaction? a. H 2 /Lindlar's Catalyst b. Na in NH 3 (l) c. H 2 /Pt d. H 2 /Ni 2 B e. a and d f. none of the above Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

22. Answer: e. The product is a cis double bond. H 2 /Lindlar's Catalyst and H 2 /Ni 2 B can both be used to turn an alkyne into a cis double bond. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

23. Alternate Answer: Section: 10.5 7. What reagent is needed for the following reaction? a. H 2 /Lindlar's Catalyst b. 1) Na in NH 3 2) NH 4 Cl c. H 2 /Pt d. H 2 /Ni 2 B e. a and d Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

24. Answer: e. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

25. Section: 10.6 8. Which of the following species is an important intermediate in a dissolving metal reduction of an alkyne to a trans alkene? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

26. Answer: b. Response: In a dissolving metal reduction, the sodium metal donates a single electron generating a radical anion, which then abstracts a proton from an ammonia molecule. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

27. Section: 10.6 9. Which reaction scheme can be used to produce this halide? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

28. Answer: a. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

29. Section: 10.6 10. One model mechanism for the Markovnikov directed hydrohalogenation of an alkyne to a vinyl halide involves a _________ molecular process where ____ molecules are involved in the key transition state, so that the overall kinetic rate law is _____ order. a.Unimolecular, one, 2 nd b.Unimolecular, two, 2 nd c.Bimolecular, two, 2 nd d.Bimolecular, three, 3 rd e.Termolecular, three, 3 rd Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

30. Answer: e. Response: A better explanation of the regioselectivity of the monohalogenation of an alkyne to a vinyl halide than a vinylic carbocation involves the formation of a 3 center transition state. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

31. Section: 10.7 11. Which reactions give ketones? Which reactions give aldehydes? I.Ketones II.Aldehydes Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

32. Answer: I: A, C, D, F II: B, E For more examples of this type of problem, see SkillBuilder 10.4. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

33. Alternate Answer: Section: 10.7 11. Which reactions give ketones (I)? Which reactions give aldehydes (II)? A. I = C, D, E, F; II = A, B B. I = B, D, E, F; II = A, C C. I = B, C, D, F; II = A, E D. I = A, D, E, F; II = B, C E. I = A, C, D, F; II = B, E Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

34. Answer: e. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

35. Section: 10.8 12. What are the product(s) of this reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

36. Answer: b. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

37. Alternate Answer: Section: 10.8 12. What are the product(s) of this reaction? A. A B. B C. C D. B and E E. D and F Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

38. Answer: b. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

39. Section: 10.7 13. During the acid catalyzed hydration of an alkyne an intermediate forms called a(n) _______, which rapidly interconverts to form a more stable _____. The two structures are said to be ___________. a.Ketone, enol, enantiomers b.Enol, ketone, enantiomers c.Ketone, enol, tautomers d.Enol, ketone, tautomers e.Ketone, enol, diastereomers Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

40. Answer: d. Response: See SkillBuilder 10.3 for more practice with keto- enol tautomerization. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

41. Section: 10.7 14. What is the major product of this reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

42. Answer: e. Response: Acid catalyzed hydration of terminal alkynes using Markovnikov directing reagents initially yields 2 o enols, which rapidly interconvert to form ketones. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

43. Section: 10.7 15. What is the major product of this reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

44. Answer: c. Response: Acid catalyzed hydration of terminal alkynes using anti-Markovnikov directing reagents like disiamylborane or 9- BBN initially yields 1 o enols, which rapidly interconvert to form aldehydes. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

45. Section: 10.9 16. What are the product(s) of this reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

46. Answer: a, d. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

47. Alternate Answers: Section: 10.9 1 6. What are the product(s) of this reaction? a. A b. B c. C d. A and D e. B and C Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

48. Answer: d. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

49. Section: 10.10 17. What is the product of the following reaction? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

50. Answer: b. For more examples of this type of problem, see SkillBuilder 10.5. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

51. Section: 10.10 18. Starting with Acetylene, what would be the appropriate set of reagents to produce 2-methyl-4-nonyne? Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

52. Answer: b. For more examples of this type of problem, see SkillBuilder 10.5. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

53. Section: 10.11 19. What is the correct order of reagents needed for the following transformation? a. xs. NaNH 2 b. NaNH 2 c. NaOMe d. H 3 O + e. Propyl Chloride f. Butyl Chloride g. Pentyl chloride Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

54. Answer: a, f. For more examples of this type of problem, see SkillBuilder 10.6. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

55. Alternate Answers: Section: 10.11 19. What is the correct order of reagents needed for the following transformation? a. xs. NaNH 2 b. NaNH 2 c. NaOMe d. H 3 O + e. Propyl Chloride f. Butyl Chloride g.Pentyl chloride A. A, E B. A, F C. A, G D. B, F E. B, G Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

56. Answer: b. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

57. Section: 10.11 20. What is the correct order of reagents needed for the following transformation? a. xs NaNH 2 b. NaOMe c. H 2 /Lindlar's Catalyst d. Na/NH 3 e. H 2 /Pt f. Propyl Chloride g. Butyl Chloride h. Pentyl chloride Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

58. Answer: a, g, e. The starting material has 5 carbons and the product has 9 carbons. Therefore, you need to add four carbons to get the product, which means you need butyl chloride. The final product has an alkane so only H 2 /Pt will produce the alkane. For more examples of this type of problem, see SkillBuilder 10.6. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

59. Alternate Answers: Section: 10.11 20. What is the correct order of reagents needed for the following transformation? a. xs NaNH 2 b. NaOMe c. H 2 /Lindlar's Catalyst d. Na/NH 3 e. H 2 /Pt f. Propyl Chloride g. Butyl Chloride h.Pentyl chloride A. A, F, C B. A, F, E C. A, G, C D. A, G, E E. A, H, C Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

60. Answer: d. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

61. Section: 10.11 21. What is the correct order of reagents needed for the following transformation? a. HBr/CCl 4 b. NaOMe c. Potassium tert-butoxide d. 1) O 3 2) H 2 O e. HBr/H 2 O 2 Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

62. Answer: e, c, d. First an anti-Markovnikov addition of HBr to the alkene places a Bromine on the second carbon. Next, elimination using potassium tert-butoxide gives the Hofmann product, a terminal alkene. Finally, oxidative cleavage gives formaldehyde and the 2-methyl-butanal product. For more examples of this type of problem, see SkillBuilder 10.6. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

63. Alternate Answers: Section: 10.11 21. What is the correct order of reagents needed for the following transformation? a. HBr/CCl 4 b. NaOMe c. Potassium tert-butoxide d. 1) O 3 2) H 2 O e. HBr/H 2 O 2 A. A, B, D B. A, C, D C. E, B, D D. E, C, D Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.

64. Answer: d. Copyright © 2015 John Wiley & Sons, Inc. All rights reserved.