Question 1

Which of the following does not give 1, 2-dimethylcyclohexene as one of the acid-catalyzed dehydration products?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)    D

Question 2

In the dehydrohalogenation of 2-bromobutane, which conformation below leads directly to the formation of cis-2-butene?

Accepted Answer

A)  only I 
B)  only II 
C)  only III 
D)  I and II 
A)  only I 
B)  only II 
C)  only III 
D)  I and II A

Question 3

Which of the following cannot undergo an E2 reaction?

Accepted Answer

A)  only I 
B)  only II 
C)  only III 
D)  I and III 
A)  only I 
B)  only II 
C)  only III 
D)  I and III A

Question 4

Which of the following would have the fastest rate of reaction to form 4-tert-butylcyclohexene?

Accepted Answer

A)  
  
B) 
  
C)  
  
D)  
  
A)  
  
B) 
  
C)  
  
D)

Question 5

Which of the alkenes below has the Z-configuration?

Accepted Answer

A)  
  
B)  
  
C)  
  
D)  
  
A)  
  
B)  
  
C)  
  
D)

Question 6

Which of the following alkenes exhibit E-Z isomerism?
I. $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHCH}_{2} \mathrm{CH}_{3}$
II. $\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{CHCH}_{3}$
III. $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}=\mathrm{CHBr}$
IV. $\mathrm{H}_{2} \mathrm{C}=\mathrm{CHCH}_{2} \mathrm{CH}\left(\mathrm{CH}_{3}\right)_{2}$

Accepted Answer

A)  I and II 
B)  I and III 
C)  II and IV 
D)  I, II, and III 
A)  I and II 
B)  I and III 
C)  II and IV 
D)  I, II, and III

Question 7

Which of the following stereoisomers gives the exclusive E2 product shown?

Accepted Answer

A) 
  
B) 
  
C) 
  
D) 
  
A) 
  
B) 
  
C) 
  
D)

Question 8

Carbon-carbon double bonds do not freely rotate like carbon-carbon single bonds. Why?

Accepted Answer

A)  The double bond is much stronger and thus more difficult to rotate. 
B)  Overlap of the two 2 p orbitals of the $\pi$ bond would be lost. 
C)  The shorter bond length of the double bond makes it more difficult for the attached groups to pass each other. 
D)  Overlap of the $\mathrm{sp}^{2}$ orbitals of the carbon-carbon $\sigma$ bond would be lost. 
A)  The double bond is much stronger and thus more difficult to rotate. 
B)  Overlap of the two 2 p orbitals of the $\pi$ bond would be lost. 
C)  The shorter bond length of the double bond makes it more difficult for the attached groups to pass each other. 
D)  Overlap of the $\mathrm{sp}^{2}$ orbitals of the carbon-carbon $\sigma$ bond would be lost.

Question 9

What is the slow, rate-determining step, in the acid-catalyzed dehydration of 2-methyl-2-propanol?

Accepted Answer

A)  Protonation of the alcohol to form an oxonium ion. 
B)  Loss of water from the oxonium ion to form a carbocation. 
C)  Loss of a $\beta$-hydrogen from the carbocation to form an alkene. 
D)  The simultaneous loss of a $\beta$-hydrogen and water from the oxonium ion. 
A)  Protonation of the alcohol to form an oxonium ion. 
B)  Loss of water from the oxonium ion to form a carbocation. 
C)  Loss of a $\beta$-hydrogen from the carbocation to form an alkene. 
D)  The simultaneous loss of a $\beta$-hydrogen and water from the oxonium ion.

Question 10

Identify the major organic product expected from the acid-catalyzed dehydration of 2-methyl-2pentanol.

Accepted Answer

A)  2-methyl-1-pentene 
B)  2-methyl-2-pentene 
C)  3-methyl-1-pentene 
D)  cis-3-methyl-2-pentene 
A)  2-methyl-1-pentene 
B)  2-methyl-2-pentene 
C)  3-methyl-1-pentene 
D)  cis-3-methyl-2-pentene

Question 11

Which of the following compounds gives a single E2 product on reaction with sodium ethoxide, $\mathrm{NaOCH}_{2} \mathrm{CH}_{3}$ ?

Accepted Answer

A)  I and II 
B)  I and III 
C)  II and III 
D)  I, II, and III 
A)  I and II 
B)  I and III 
C)  II and III 
D)  I, II, and III

Question 12

If you wanted to make compound III, starting with compound I or II, what would you do?

Accepted Answer

A)  React I with $\mathrm{H}_{2} \mathrm{SO}_{4}$. 
B)  React II with NaOEt. 
C)  Either of the reactions in A or B above would work. 
D)  Neither of the reactions in A or B above would work. 
A)  React I with $\mathrm{H}_{2} \mathrm{SO}_{4}$. 
B)  React II with NaOEt. 
C)  Either of the reactions in A or B above would work. 
D)  Neither of the reactions in A or B above would work.

Question 13

Which of the following carbocations is(are) likely to undergo a rearrangement?

Accepted Answer

A)  only I 
B)  I and III 
C)  II and III 
D)  I, II, and III 
A)  only I 
B)  I and III 
C)  II and III 
D)  I, II, and III

Question 14

What is the IUPAC name of the following compound?

Accepted Answer

A)  2-methyl-3-propyl-2-pentene 
B)  3-ethyl-2-methyl-2-hexene 
C)  4-ethyl-5-methyl-4-hexene 
D)  4-methyl-3-propyl-3-pentene 
A)  2-methyl-3-propyl-2-pentene 
B)  3-ethyl-2-methyl-2-hexene 
C)  4-ethyl-5-methyl-4-hexene 
D)  4-methyl-3-propyl-3-pentene

Question 15

What is the major product of the reaction sequence shown below?

Accepted Answer

A)  2-methyl-1-butene 
B)  2-methyl-2-butene 
C)  3-methyl-1-butene 
D)  2-methylbutane 
A)  2-methyl-1-butene 
B)  2-methyl-2-butene 
C)  3-methyl-1-butene 
D)  2-methylbutane

Question 16

Which of the following $\mathrm{C}_{6} \mathrm{H}_{12}$ isomers has the highest heat of combustion?

Accepted Answer

A)  1-hexene 
B)  trans-3-hexene 
C)  cis-3-hexene 
D)  2-methyl-2-pentene 
A)  1-hexene 
B)  trans-3-hexene 
C)  cis-3-hexene 
D)  2-methyl-2-pentene

Question 17

Predict the major product of the following reaction.

Accepted Answer

A)  
  
B)  
  
C)  
  
D)  
  
A)  
  
B)  
  
C)  
  
D)

Question 18

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

Accepted Answer

A)  the loss of $\mathrm{OH}^{-}$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 $\beta$-hydrogen from the alcohol 
A)  the loss of $\mathrm{OH}^{-}$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 $\beta$-hydrogen from the alcohol

Exam 5: Structure and Preparation of Alkenes: Elimination Reactions

Which of the following does not give 1, 2-dimethylcyclohexene as one of the acid-catalyzed dehydration products?

In the dehydrohalogenation of 2-bromobutane, which conformation below leads directly to the formation of cis-2-butene?

Which of the following cannot undergo an E2 reaction?

Which of the following would have the fastest rate of reaction to form 4-tert-butylcyclohexene?

Which of the alkenes below has the Z-configuration?

Which of the following stereoisomers gives the exclusive E2 product shown?

Carbon-carbon double bonds do not freely rotate like carbon-carbon single bonds. Why?

What is the slow, rate-determining step, in the acid-catalyzed dehydration of 2-methyl-2-propanol?

Identify the major organic product expected from the acid-catalyzed dehydration of 2-methyl-2pentanol.

Which of the following compounds gives a single E2 product on reaction with sodium ethoxide, NaOCH2CH3\mathrm{NaOCH}_{2} \mathrm{CH}_{3}NaOCH2​CH3​ ?

If you wanted to make compound III, starting with compound I or II, what would you do?

Which of the following carbocations is(are) likely to undergo a rearrangement?

What is the IUPAC name of the following compound?

What is the major product of the reaction sequence shown below?

Which of the following C6H12\mathrm{C}_{6} \mathrm{H}_{12}C6​H12​ isomers has the highest heat of combustion?

Predict the major product of the following reaction.

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

Structure Determines Properties

Alkanes and Cycloakanes: Introduction to Hydrocarbons

Alkanes and Cycloalkanes: Introduction to Stereochemistry

Alcohols and Alkyl Halides: Introduction to Reaction Mechanisms

Addition Reactions of Alkenes

Chirality

Nucleophilic Substitution

Alkynes

Spectroscopy

Organometallic Compounds

Alcohols, Diols, and Thiols

Ethers, Epoxides, and Sulfides

Aldehydes and Ketones: Nucleophilic Addition to the Carbonyl Group

Carboxylic Acids

Acid Derivatives

Enols and Enolates

Amines

Phenols

Carbohydrates

Lipids

Amino Acids, Peptides, and Proteins

Nucleosides, Nucleotides, and Nucleic Acids

Synthetic Polymers

Filters

Which of the following compounds gives a single E2 product on reaction with sodium ethoxide, $\mathrm{NaOCH}_{2} \mathrm{CH}_{3}$ ? $Which of the following compounds gives a single E2 product on reaction with sodium ethoxide, \mathrm{NaOCH}_{2} \mathrm{CH}_{3} ?$

Which of the following $\mathrm{C}_{6} \mathrm{H}_{12}$ isomers has the highest heat of combustion?