Question 1

It has been found that b-dicarbonyl compounds have a greater concentration of the enol form over the keto form.This can be explained by

Accepted Answer

A)  the C=C of the enol is conjugated with the carbonyl group.
B)  the -OH of the enol can hydrogen bond to the oxygen of the nearby carbonyl group.
C)  Both and above are true.
D)  None of the choices are true.E) None of the above
F) B) and D)

Question 2

Which of the following compounds would undergo racemization in the presence of a base?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) A) and C)
F) B) and C)

Question 3

Starting with cyclohexanone,how could you prepare the diketone below?

Accepted Answer

A)  Treat cyclohexanone with a base under thermodynamic conditions.
B)  Hydrogenate cyclohexanone with Raney nickel.
C)  Convert cyclohexanone into the a-bromoketone and then react this with the enolate of cyclohexanone.
D)  Convert cyclohexanone into an enamine with diethylamine and then react this with more cyclohexanone.E) A) and B)
F) C) and D)

Question 4

Which of the following bases will completely convert 1,4-cyclohexandione into an enolate?

Accepted Answer

A)  Sodium hydroxide
B)  Sodium methoxide
C)  Sodium tert-butoxide
D)  Sodium hydrideE) None of the above
F) B) and D)

Question 5

Which of the following is the least acidic compound?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) A) and C)
F) B) and C)

Question 6

Which of the following is an enol form of the following compound?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) C) and D)
F) A) and D)

Question 7

The following molecule is called

Accepted Answer

A)  a 1,3-diketopentanoate.
B)  a diethyl malonate.
C)  an ethyl acetoacetate.
D)  a b-keto ester.E) B) and C)
F) A) and B)

Question 8

What is the missing reagent in the reaction below? 2/AcOH B) I2/KOH C) I2 D) KOH" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  Br2/AcOH
B)  I2/KOH
C)  I2
D)  KOHE) C) and D)
F) A) and D)

Question 9

For most compounds with a single keto group in the molecule,equilibrium favors the keto form over the enol form of the compound.This is due largely to what?

Accepted Answer

A)  The C=O bond is much stronger than the C=C bond.
B)  The C=C bond is much stronger than the C=O bond.
C)  The keto form can undergo intramolecular hydrogen bonding.
D)  The enol form can undergo intramolecular hydrogen bonding.E) A) and D)
F) A) and C)

Question 10

Why can't you prepare 2-tert-butylcyclohexanone by the following reaction? N2 reaction. C) Because tert-butyl bromide is a nucleophile. D) Because tert-butyl bromide is not a stable compound." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  Because tert-butyl bromide is too basic.
B)  Because tert-butyl bromide cannot undergo an SN2 reaction.
C)  Because tert-butyl bromide is a nucleophile.
D)  Because tert-butyl bromide is not a stable compound.E) All of the above
F) B) and D)

Question 11

What is the missing reagent for the following reaction? 2/HOAc B) Br2/KOH C) Cl2/FeCl3 D) Br2/FeBr3" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  Br2/HOAc
B)  Br2/KOH
C)  Cl2/FeCl3
D)  Br2/FeBr3E) C) and D)
F) B) and D)

Question 12

Which of the following compounds is the most acidic?

Accepted Answer

A)  Ethyl acetoacetate
B)  2-Butanone
C)  1-Butanol
D)  3-PentanoneE) A) and B)
F) All of the above

Question 13

Which is the most acidic proton in the following compound?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) B) and D)
F) All of the above

Question 14

Which of the following four compounds is the most acidic?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) None of the above
F) A) and B)

Question 15

Why is the enolate of acetone less basic than the allyl anion derived from propene?

Accepted Answer

A)  Because there are more atoms in acetone
B)  Because there are more resonance structures for the enolate of acetone
C)  It isn't; the allyl anion is less basic.
D)  One of the resonance structures for the enolate places the negative charge on the more electronegative oxygen.E) B) and D)
F) B) and C)

Question 16

Will acetophenone be completely deprotonated by lithium diisopropylamide (LDA) ?

Accepted Answer

A)  Yes
B)  NoC) A) and B)
D) undefined

Question 17

If you want to form a kinetic enolate,you want to

Accepted Answer

A)  use a strong,non-nucleophilic base such as LDA.
B)  use a protic solvent.
C)  use a low temperature.
D)  both use a strong,non-nucleophilic base such as LDA and use a low temperature.E) C) and D)
F) B) and D)

Question 18

What is the starting material for the following reaction?

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) A) and B)
F) A) and C)

Question 19

Treatment of 2-hexanone with NaOCH2CH3 followed by CH3Br affords compound X (C7H14O) as the major product.X shows a strong absorption in the IR spectrum at 1713 cm-1,and its 1H NMR data is given below.What is the structure of X? 2CH3 followed by CH3Br affords compound X (C7H14O) as the major product.X shows a strong absorption in the IR spectrum at 1713 cm-1,and its 1H NMR data is given below.What is the structure of X?       A) I B) II C) III D) IV" class="answers-bank-image d-inline" rel="preload" > 2CH3 followed by CH3Br affords compound X (C7H14O) as the major product.X shows a strong absorption in the IR spectrum at 1713 cm-1,and its 1H NMR data is given below.What is the structure of X?       A) I B) II C) III D) IV" class="answers-bank-image d-inline" rel="preload" > 2CH3 followed by CH3Br affords compound X (C7H14O) as the major product.X shows a strong absorption in the IR spectrum at 1713 cm-1,and its 1H NMR data is given below.What is the structure of X?       A) I B) II C) III D) IV" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)  I
B)  II
C)  III
D)  IVE) B) and C)
F) A) and D)

Question 20

What are the three steps in the malonic ester synthesis?

Accepted Answer

A)  Deprotonation,alkylation,hydrolysis/decarboxylation
B)  Hydrogenation,alkylation,deprotonation
C)  Alkylation,hydrolysis/decarboxylation.hydrogenation
D)  Hydrolysis/decarboxylation,deprotonation,alkylationE) B) and D)
F) C) and D)

Exam 21: Substitution Reactions of Carbonyl Compounds at the a Carbon

The following molecule is called

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What is the starting material for the following reaction?

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Which of the following four compounds is the most acidic?

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Which is the most acidic proton in the following compound?

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Why can't you prepare 2-tert-butylcyclohexanone by the following reaction?

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For most compounds with a single keto group in the molecule,equilibrium favors the keto form over the enol form of the compound.This is due largely to what?

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What are the three steps in the malonic ester synthesis?

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What is the missing reagent in the reaction below?

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Which of the following is the least acidic compound?

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Which of the following is an enol form of the following compound?

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Which of the following compounds is the most acidic?

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Which of the following compounds would undergo racemization in the presence of a base?

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Why is the enolate of acetone less basic than the allyl anion derived from propene?

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Starting with cyclohexanone,how could you prepare the diketone below?

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It has been found that b-dicarbonyl compounds have a greater concentration of the enol form over the keto form.This can be explained by

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Treatment of 2-hexanone with NaOCH2CH3 followed by CH3Br affords compound X (C7H14O) as the major product.X shows a strong absorption in the IR spectrum at 1713 cm-1,and its 1H NMR data is given below.What is the structure of X?

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If you want to form a kinetic enolate,you want to

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Which of the following bases will completely convert 1,4-cyclohexandione into an enolate?

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What is the missing reagent for the following reaction?

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Will acetophenone be completely deprotonated by lithium diisopropylamide (LDA) ?

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Treatment of 2-hexanone with NaOCH₂CH₃ followed by CH₃Br affords compound X (C₇H₁₄O) as the major product.X shows a strong absorption in the IR spectrum at 1713 cm^-1,and its ¹H NMR data is given below.What is the structure of X?

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