Chemistry 231 June 22, 2000 Examination No. 2 - 100 Points

I. PART I: TRUE/FALSE: 20 POINTS 2 Pts each

1.

T

F

2-methyl-1-hexene will oxidize a purple solution of KMnO4.
       

2.

T

F

An acceptable name for the following compound is:

3-bromo-1-isopropylcyclohexene

 

 

 

 

 

 
       

3.

T

F

4-methyl-2-pentene will undergo Catalylic Hydrogenation to form isopentane.
       

4.

T

F

cis-1,4-diethylcyclohexane is achiral.
       

5.

T

F

1-t-butyl-3-ethylcyclohexene has one (1) vinylic hydrogen and two (2) allylic hydrogen atoms.
       

6.

T

F

2,4-dichloropentane has a meso stereoisomer.
       

7.

T

F

 

 

 

 

 

 

Has a (E) configuration at the double bond.
       

8.

T

F

The following compound has six (6) chiral (stereogentic} carbon atoms.

 

 

 

 

.

 
       

9.

T

F

An acceptable name for the following compound is:

5,5,6,7-tetramethyl-6-octen-2-ol

 

 

 
       

10.

T

F

An enantiomer of (S)-4-bromo-(Z)-2-hexene is

(R)-4-bromo-(E)-2-henene.
       

II. PART II: MULTIPLE CHOICE: 45 POINTS 3 Pts each

1. Which of the following is true about any (R) enantiomer?

a. It is dextrorotatory

b. (R) indicates a racemic mixture (racemate)

c. It is the non-superimposable mirror image of the (S) enantiomer

d. It is levorotatory

e. It is an equal molar mixture of the (+) and (-) enantiomers

2. Which alcohol cannot be prepared from an alkene by Hydroboration-Oxidation or Acid-Catalyzed Hydration?

a. 1-pentanol

b. 2-pentanol

c. 2-methyl-1-butanol

d. 3-methyl-1-butanol

e. no answer shown

3. The monomer used to make Orlon is:

 

 

 

 

 

 

 

 

4. How many stereoisomers (total) are possible for:

 

 

 

a. none

b. two

c. four

d. six

e. eight

5. Which of the following does not give 1,2-dimethylcyclohexene as one of the Acid-Catalyzed Dehydration products?

 

 

 

 

a. 1

b. 2

c. 3

d. 4

6. When 2,2-dimethylpentane undergoes photochemical monochlorination, a mixture of monochlorinated isomers are formed. How many of these isomers are isolated as racemates?

a. two

b. three

c. four

d. five

e. no answer shown

7. Which structure corresponds to the trimer of isobutylene (2-methylpropene) formed under conditions of Cationic Polymerization?

 

 

 

 

a. 1

b. 2

c. 3

d. 4

e. no answer shown

8. What is the first step in the mechanism of the Dehydration reaction of a tertiary alcohol with sulfuric acid to form an alkene?

a. The loss of OH- to form a carbocation.

b. The protonation of the hydroxyl group.

c. The loss of the proton from the hydroxyl group to give an alkoxide ion.

d. The removal of a b -Hydrogen from the alcohol.

e. loss of H2O.

9. Which group has the highest priority by the Cahn-Ingold-Prelog rules?

 

 

10. What is the relationship between the following two molecules?

 

 

 

 

a. identical compounds

b. enantiomers

c. diastereoisomers

d. constitutional isomers

e. conformational isomers

11. How many alkenes of molecular formula C7H14 , will be formed when 2-iodo-3-methylhexane undergoes a Dehydrohalogenation in the presence of a strong base. Be sure to include all

Z/E isomers in your total.

a. two

b. three

c. four

d. five

e, no answer shown

12. What is the number of open-chained, monoenes of molecular formula C6H12 that do not

form Z/E geometric isomers?

a. three

b. four

c. five

d. six

e. no answer shown

13. One mole of each of the following alkenes is subjected to catalytic hydrogenation. Which one would you expect to liberate the least amount of heat?

 

 

 

 

 

 

 

14. Which of the following correctly depicts the mechanistic first step in the ionic addition of HBr to 2-methylpropene (isobutylene):

 

 

 

 

a. 1

b. 2

c. 3

d. 4

15. What is an acceptable name for the following compound?

a. 7-ethyl-2-methyl-6-nonene

b. 3-ethyl-7-isopropyl-3-octene

c. 3-ethyl-8-methyl-3-nonene

d. 1,1-diethyl-6-methyl-3-heptene

e. no answer shown

 

III. PART III: 35 POINTS

9 Pts

1. State whether the following pairs of compounds are identical, constitutional isomers, enantiomers, diastereoisomers or conformational isomers of each other:

a.

 

 

 

 

 

 

b.

 

 

 

 

 

c.

 

 

 

 

 

 

 

 

12 Pts

2. Draw the structural formulas for the missing organic reagent or the missing major organic productfor each of the following organic reactions. In cases marked with an *, show the proper stereochemistry of the organic producct. All reactions take place as written.

*1.

 

 

 

  
 

ORGANIC PRODUCT

*2.

 

 

 

  

ORGANIC PRODUCT

3.

 

 

 

 

 

 

 

 

 

ORGANIC REAGENT

  

 

4.

 

 

 

 

 

  

ORGANIC REAGENT

  
   

5.

 

 

 

 

  
 

ORGANIC PRODUCT
   

6.

 

 

 

  
 

ORGANIC PRODUCT

2 Pts

3. Gve an equation for the Rate-Determining step in the Free-Radical Addition of HBr

to 1-butene to form 1-bromobutane:

12 Pts

4. LABORATORY CONVERSIONS: By means of unbalanced organic reactions, show the complete step-by-step laboratory conversions for each of the following: You may use any required organic or inorganic reagents. Do not show any mechanisms.

a.