New York University

BIOCHEMIST 406

1)Which of the following statements is true about the solubility of alkenes?

1. 1. all alkenes are soluble in water
   2. long chain alkenes are soluble in water, but short chain alkenes are insoluble
   3. long chain alkenes are insoluble in water, but short chain alkenes are soluble
   4. all alkenes are soluble in alkanes

2. What is the molecular formula of isoprene, the building block of all terpenes?
   1. C₅H₆
   2. C₅H₈
   3. C₆H₁₀
   4. C₅H₁₂

3. How many double bonds are present in isoprene, the building block of terpenes?
   1. 0
   2. 1
   3. 2
   4. 3

4. Which of the following compounds have the carbon skeleton of a terpene?

1. 1. compounds (i) and (ii)
   2. compounds (i) and (iii)
   3. compounds (ii) and (iii)
   4. only compound (i)

5. How many isoprene units are present in the following natural terpene?

1. 1. 2
   2. 3
   3. 4
   4. 5

6. Vitamin A contains four isoprene units. Which of the following represents the molecular formula of vitamin A?
   1. C₄H₈O
   2. C₁₀H₁₈O
   3. C₂₀H₃₀O
   4. C₄₀H₆₀O

7. The structure of farnesol contains three isoprene units. Which of the following represents the molecular formula of farnesol?
   1. C₁₀H₁₆O
   2. C₁₀H₁₅O
   3. C₁₅H₂₆O
   4. C₂₀H₃₀O

8. Which of the following is not an intermediate in the biosynthesis of cholesterol?
   1. farnesol
   2. geraniol
   3. retinol
   4. none, they are all intermediates in the synthesis of cholesterol

9. Which of the following is the most characteristic reaction of alkenes?
   1. addition
   2. oxidation
   3. reduction
   4. substitution

10. Which of the following reactions involves the addition of two equivalent groups to the two ends of a double bond?
    1. hydrogenation
    2. hydrobromination
    3. both (a) and (b)
    4. neither (a) nor (b)

11. Which of the following reactions involves the addition of two equivalent groups to the two ends of a double bond?
    1. hydration
    2. hydrogenation
    3. both (a) and (b)
    4. neither (a) nor (b)

12. Which of the following reactions involves the addition of two equivalent groups to the two ends of a double bond?
    1. bromination
    2. hydrogenation
    3. both (a) and (b)
    4. neither (a) nor (b)

13. Which of the following reactions involves the addition of different groups to the two ends of a double bond?
    1. hydrogenation
    2. hydrobromination
    3. both (a) and (b)
    4. neither (a) nor (b)

14. Which of the following reactions involves the addition of different groups to the two ends of a double bond?
    1. hydration
    2. hydrogenation
    3. both (a) and (b)
    4. neither (a) nor (b)

15. Which of the following reactions involves the addition of different groups to the two ends of a double bond?
    1. bromination
    2. hydrogenation
    3. both (a) and (b)
    4. neither (a) nor (b)

16. Which of the following curved arrows correctly describes the first step of the reaction of propene with a hydrogen halide?

A.

B.

C.

D. none of these are correct

17. Which of the following curved arrows correctly describes the second step in the reaction of propene with hydrogen bromide?

A.

B.

C.

D.

18. Markovnikov's rule is not useful for predicting the outcome of the reaction of hydrogen chloride with which of the following alkenes?
    1. 1-butene
    2. 2-butene
    3. 2-methylpropene
    4. 1-pentene

19. Markovnikov's rule is useful to predict the outcome of the reaction of hydrogen chloride with which of the following alkenes?
    1. 1-butene
    2. 2-butene
    3. both (a) and (b)
    4. neither (a) nor (b)

20. Markovnikov?s rule is useful in predicting the outcome for which of the following addition reactions of unsymmetrical alkenes?
    1. hydration
    2. bromination
    3. both (a) and (b)
    4. neither (a) nor (b)

21. Which of the listed products will be formed in the following reaction?

22. Which of the listed products will be formed in the following reaction?

B.

C.

D.