New York University

BIOCHEMIST 406

1)A student named a particular compound 2-ethyl-3-methyl-2-butene. Assuming that the student's choice actually corresponded to the correct distribution of the double bond and the substituents, what is the correct IUPAC name for this compound?

1. 1. 2-ethyl-3-methyl-2-butene
   2. 3,4-dimethyl-3-pentene
   3. 2,3-dimethyl-2-pentene
   4. 2,3-dimethyl-1-pentene

2. A student wanted to use the branched groups, isobutyl, sec-butyl, and tert-butyl when naming alkenes, but was told not to. What is the correct IUPAC name for the compound the student called isobutylethene?
   1. 4-methyl-1-pentene
   2. 3-methyl-1-pentene
   3. 3,3-dimethyl-1-butene
   4. none of these

3. A student wanted to use the branched groups, isobutyl, sec-butyl, and tert-butyl when naming alkenes, but was told not to. What is the correct IUPAC name for the compound the student called sec-butylethene?
   1. 4-methyl-1-pentene
   2. 3-methyl-1-pentene
   3. 3,3-dimethyl-1-butene
   4. none of these

4. What is the correct IUPAC name for the following compound

?

1. 1. 2-methyl-3-propyl-2-butene
   2. 1,1,2-trimethyl-1-pentene
   3. 2,3-dimethyl-2-hexene
   4. none of these

5. What is the name of the lightest hydrocarbon which has cis and trans isomers?
   1. 1-butene
   2. 2-butene
   3. 1,2-dimethylcyclopropane
   4. Propene

6. Cis-trans isomers exist for which of the following molecules, all of which have the molecular formula C₃H₅Br?
   1. 1-bromopropene
   2. 2-bromopropene
   3. 3-bromopropene
   4. none of these

7. Cis-trans isomers do not exist for which of the following compounds, all of which have the molecular formula C₃H₄Br₂?
   1. 1,1-dibromopropene
   2. 1,2-dibromopropene
   3. 1,3-dibromopropene
   4. they do not exist for any of these three molecules

8. Which of the following, all of which have the molecular formula C₅H₁₀, has cis and trans isomers?
   1. 2-methyl-1-butene
   2. 2-methyl-2-butene
   3. 2-pentene
   4. none of them

9. Cis-trans isomers exist for which of the following molecules, all of which have the molecular formula C₅H₁₀?
   1. 1-pentene
   2. 2-methyl-1-butene
   3. 2-methyl-2-butene
   4. 1,2-dimethylcyclopropane

10. Which of the following structures corresponds to cis-3-methyl-2-hexene A.

B.

C.

D.

11. Which of the following compounds, all of which have the molecular formula C₆H₁₂, has cis and trans

isomers?

1. 1. 2-methyl-1-pentene
   2. 2-methyl-2-pentene
   3. 3-methyl-2-pentene
   4. they all have cis-trans isomers

12. Which of the following compounds, all of which have the molecular formula C₆H₁₂, does not have cis and

trans isomers?

1. 1. 4-methyl-2-pentene
   2. 2-methyl-1-pentene
   3. 3-methyl-2-pentene
   4. none of them, they all have cis-trans isomers

13. What is the correct IUPAC name for the following compound: ?
    1. trans-3-propyl-3-hexene
    2. cis-3-propyl-3-hexene
    3. trans-4-ethyl-3-heptene
    4. cis-4-ethyl-3-heptene

14. What is the configuration of each of the alkenes shown below?

1. 1. (i) cis (ii) cis
   2. (i) trans (ii) trans
   3. (i) cis (ii) trans
   4. (i) trans (ii) cis

15. Stereoisomers exist for which of the following molecules, all of which have the molecular formula C₅H₈?
    1. 1,3-pentadiene
    2. 1,4-pentadiene
    3. 2-methyl-1,3-butadiene
    4. all of them

16. Including cis-trans isomers, how many different alkenes have the molecular formula C₄H₈?
    1. 2
    2. 3
    3. 4
    4. 5

17. Including cis-trans isomers, how many different alkenes have the molecular formula C₅H₁₀?
    1. 4
    2. 5
    3. 6
    4. 7

18. How many cycloalkenes have the molecular formula C₄H₆?
    1. 1
    2. 2
    3. 3
    4. 4

19. How many cycloalkenes have the molecular formula C₅H₈?
    1. 7
    2. 8
    3. 9
    4. 10

20. Which of the following is not a correct IUPAC name?
    1. 3-methylcyclopentene
    2. 4-methylcyclopentene
    3. 5-methylcyclopentene
    4. none, they are all correct

21. Which of the following is a correct IUPAC name?
    1. 4-ethyl-1-methylcyclohexene
    2. 5-ethyl-2-methylcyclohexene
    3. 1-methyl-4-ethylcyclohexene
    4. 5-methyl-2-ethylcyclohexene

22. Which of the following is not a correct IUPAC name?
    1. cis-2,3-dimethylcyclopentene
    2. cis-3,4-dimethylcyclopentene
    3. cis-3,5-dimethylcyclopentene
    4. none, they are all correct

23. Cis-trans isomers exist for which of the following?
    1. 1,2-dimethylcyclopentene
    2. 2,3-dimethylcyclopentene
    3. 3,5-dimethylcyclopentene
    4. all of them

24. How many stereoisomers are possible for 1,4-heptadiene?
    1. 2
    2. 4
    3. 7
    4. 8

25. How many stereoisomers are possible for 2,4-heptadiene?
    1. 2
    2. 4
    3. 7
    4. 8

26. How many stereoisomers are possible for 1,4,7-octatriene?
    1. 2
    2. 4
    3. 8
    4. 16

27. How many stereoisomers are possible for 1,4,6-octatriene?
    1. 2
    2. 4
    3. 8
    4. 16