CHEM 210
[ CHAPTER 11 - A LKYNES]
1. Give the IUPAC name for the following compound. CH3C(CH3)2CH2C
CCH2CH(CH2CH2CH3)CH3
A) 2,2,7‐trimethyl‐4‐undecyne B) 2,2,7‐trimethyl‐4‐nonyne C) 3,3,7‐trimethyl‐4‐decyne D) 2,2,7‐trimethyl‐4‐decyne E) 2,2,6‐trimethyl‐4‐undecyne 2. Give the IUPAC name for the following compound. CH3C
CCH2C(CH3)3
A) 4,4‐dimethyl‐2‐hexyne B) 5,5‐dimethyl‐2‐hexyne C) 5,5‐dimethyl‐3‐hexyne 3. Rank the following compounds in order of increasing basicity.
A) a < b < c D) b < a < c B) b < c < a E) c < b < a C) c < a < b 4. Which of the of the circled hydrogens is the least acidic?
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CHEM 210
[ CHAPTER 11- A LKYNES]
5. Determine the product of the following reaction.
6. Determine the product of the following reaction.
7. Determine the product of the following reaction.
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CHEM 210
[ CHAPTER 11- A LKYNES]
8. Determine the product(s) of the following reaction.
9. Determine the product of the following reaction.
10. Determine the product of the following reaction.
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CHEM 210
[ CHAPTER 11- A LKYNES]
11. Determine the product of the following reaction.
12. Determine the product of the following reaction.
13. Determine the product(s) of the following reaction.
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CHEM 210
[ CHAPTER 11- A LKYNES]
14. What is the starting material in the reaction below?
15. What is the reagent for the following reaction?
A) SOCl2 D) Cl2 B) 2HCl E) Br2/CCl4 C) 2TsCl 16. Which of the following is a keto‐enol tautomeric pair?
17. Consider the dicarbonyl compound A drawn below. Which of the following compounds can be an enol tautomer of A?
A) a only D) a and b B) b only E) a and c C) c only 5
CHEM 210
[ CHAPTER 11- A LKYNES]
18. Which of the following compounds is (are) a tautomer of compound A drawn below?
A) a B) b C) c D) Compounds a and b are both tautomers of A. E) Compounds a, b and c are all tautomers of A. 19. Which of the following anions is most basic? A) CH3 – D) HC C – B) H2C CH – E) CH3C C – C) (CH3)3C – 20. In the addition of HBr to 1‐butyne, the electrophile is: A) the Csp –Hs bond of 1‐butyne. B) the CºC triple bond of 1‐butyne. C) H+ ion. D) Br – ion. E) the C‐2 carbon atom of 1‐butyne. 21. Predict the major product B from the reaction sequence shown below.
A) Butane D) 2‐butyne B) Cis‐2‐butene E) 1‐butyne C) Trans‐2‐butene 22. Which method would work the best in carrying out the following conversion?
A) (1) HBr; (2) 2 NaNH2 B) (1) Br2; (2) 2 NaNH2 C) (1) Br2, H2O; (2) NaNH 2 D) (1) BH3, THF; (2) H2O2, NaOH ; (3) NaNH2 E) (1) NaNH2 6
CHEM 210
[ CHAPTER 11- A LKYNES]
23. How would you carry out the following conversion:
A) (1) H2O, H2SO4/HgSO4; (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) Aqueous H2SO4 24. What is the relationship between the keto and enol forms of acetone, CH3COCH3? A) Same compounds B) Diastereoisomers C) Conformational isomers D) Constitutional isomers E) Resonance structures Challenge Questions 25. Terminal alkynes can be converted to acetylide ions with a strong base. Determine the product from the following reaction sequence used in the synthesis of Spirastrellolide B. Note: “THP” and “Bn” are used as protecting groups for the alcohol moieties and can be ignored for the purpose of determining the answer to this question.
26. Provide an IUPAC name for the following compound.
A) (2R, 3S, 4R)‐4‐benzyl‐3‐fluoro‐5‐heptyn‐2‐ol B) (2S, 3R, 4R)‐4‐benzyl‐3‐fluoro‐5‐heptyn‐2‐ol C) (2S, 3R, 4S)‐ 3‐fluoro‐4‐phenyl‐5‐heptyn‐2‐ol D) (2R, 3S, 4R)‐3‐benzyl‐4‐fluoro‐2‐heptyn‐5‐ol E) (2S, 3R, 4S)‐3‐benzyl‐4‐fluoro‐2‐heptyn‐5‐ol 7
CHEM 210
[ CHAPTER 11- A LKYNES]
27. Determine which of the reagents below is not used in the synthesis of the target alcohol from ethyne.
28. An aqueous solution of formic acid can be used to promote a ring‐closing reaction. Think about a possible mechanism for this reaction and determine the structure of the product.
29. Identify the product that results from the following sequence of reactions.
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CHEM 210 Answer Key ‐ Chapter 11: Alkynes
1. D 2. B 3. A 4. E 5. D 6. A 7. C 8. A 9. E 10. A 11. B 12. B 13. B 14. A 15. B 16. C 17. E 18. D 19. C 20. C 21. C 22. B 23. C 24. D 25. C 26. A 27. D 28. B 29. E
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[ CHAPTER 11- A LKYNES]
