Deck 17: Carbonyl Alpha-Substitution and Condensation Reactions

Question 1

Instructions: Consider the structures below to answer the following question(s).

Refer to instructions.Rank the molecules above in order of increasing acidity (least acidic to most acidic).

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

Answer 1

II,III,I

Question 2

Instructions: Consider the reaction sequence below to answer the following question(s).


Refer to instructions.The starting material A in this reaction sequence is called a(n)_____.

A)b-keto ester
B)a-carboethoxy ketone
C)malonic ester
D)acetoacetic ester

Answer 2

b-keto ester

Question 3

Instructions: Consider the structures below to answer the following question(s).

Refer to instructions.Underline the acidic hydrogen atoms in each of the molecules.

Answer 3

most

Question 4

Instructions: Consider the reaction below to answer the following question(s).


Refer to instructions.The product of this reaction is:

A)a b,g-unsaturated aldehyde
B)an a,b-unsaturated ketone
C)an a,b-unsaturated aldehyde
D)an enol

Question 5

Instructions: Draw the structure of the aldol self-condensation product of each compound for the following question(s).If a compound does not undergo aldol self-condensation,explain why it does not.
Draw and explain:

Question 6

Instructions: Give the major organic product(s)of each reaction or sequences of reactions for the following question(s).Show all relevant stereochemistry.
Give major product(s):

Question 7

Instructions: Consider the reaction below to answer the following question(s).

Refer to instructions.Write the complete stepwise mechanism for the reaction above.Show all intermediate structures and all electron flow with arrows.

Question 8

Instructions: Give the major organic product(s)of each reaction or sequences of reactions for the following question(s).Show all relevant stereochemistry.
Give major product(s):

Question 9

Instructions: Each of the following compounds in the following question(s)can be prepared by a mixed aldol condensation reaction.
a)Give the structures of the aldehyde and/or ketone precursors for each aldol condensation product and formulate the reaction.
b)Give the structure of the intermediate aldol product.

Refer to instructions.Use the following compound:

Question 10

Instructions: Draw the structure of the aldol self-condensation product of each compound for the following question(s).If a compound does not undergo aldol self-condensation,explain why it does not.
Draw and explain:

Question 11

How would you prepare 5-methyl-2-hexanone using an acetoacetic ester synthesis?

Question 12

Instructions: Consider the reaction sequence below to answer the following question(s).

Refer to instructions.Conversion of B into C involves hydrolysis of the ester followed by decarboxylation.On the structures provided below,show the electron flow for the decarboxylation step.

Question 13

How would you prepare 3-phenylpropanoic acid using a malonic ester synthesis?

Question 14

Instructions: Each of the following compounds in the following question(s)can be prepared by a mixed aldol condensation reaction.
a)Give the structures of the aldehyde and/or ketone precursors for each aldol condensation product and formulate the reaction.
b)Give the structure of the intermediate aldol product.

Refer to instructions.Use the following compound:

Question 15

Instructions: Draw the structure of the aldol self-condensation product of each compound for the following question(s).If a compound does not undergo aldol self-condensation,explain why it does not.

Draw and explain:

Question 16

Instructions: Consider the reaction sequence below to answer the following question(s).


Refer to instructions.Conversion of A into B is a type of reaction termed _____.

A)an acylation
B)an enolation
C)an alkylation
D)a phenylation

Question 17

Instructions: Consider the reaction below to answer the following question(s).

Refer to instructions.Which carbonyl compound functions as the electrophile in this reaction?

A)A
B)B
C)C

Question 18

Instructions: Consider the reaction below to answer the following question(s).

Refer to instructions.Draw the structure of the enolate ion that is generated during the course of this reaction.

Question 19

Instructions: Each of the following compounds in the following question(s)can be prepared by a mixed aldol condensation reaction.
a)Give the structures of the aldehyde and/or ketone precursors for each aldol condensation product and formulate the reaction.
b)Give the structure of the intermediate aldol product.
Refer to instructions.Use the following compound:

Question 20

Instructions: Consider the reaction below to answer the following question(s).


Refer to instructions.This reaction is an example of:

A)an intramolecular Claisen condensation
B)an intramolecular aldol condensation
C)a Robinson annulation
D)a Michael reaction

Question 21

The common feature of a-substitution and condensation reactions of carbonyl groups:

A)involve two carbonyl partners
B)involve the formation of an enol or enolate ion
C)involve a nucleophile
D)produce a new carbon to carbon bond
E)all of these describe both types of reactions

Question 22

Which of the following is common to both tautomers and resonance forms of a compound?

A)have the same molecular formula
B)differ only in the position of electrons
C)rapidly interconvertible
D)differ in connectivity of atoms
E)all of these describe both tautomers and resonance forms

Question 23

Which of the following would form an enolate ion on treatment with a base?

A)A
B)B
C)C
D)D
E)All of these except C

Question 24

Which of the following are intermediates in the acid catalyzed aldol reaction of propanal to form 2-methyl-pent-2-enal?

A)only 1 and 2
B)only 1,3 and 4
C)only 2,3 and 4
D)1,2,3 and 4

Question 25

Rank the following hydrogens in terms of decreasing acidity (most acidic > least acidic):

Question 26

Which of the following does not possess an enol form? Explain your choice.

Question 27

Instructions: The Stork enamine reaction is a variation on the Michael reaction that utilizes an enamine nucleophile.Use this information to answer the following question.

Refer to instructions.Draw the structures of the ketone and amine products of this reaction.

Question 28

Which of the following would form an enol on treatment with an acid?

A)4-chlorobenzaldehye
B)2,2,-dimethylbutanal
C)2,2,4,4-tetrachlorohexan-3-one
D)none of these

Question 29

When treated with base and heat,the following diketone undergoes an intramolecular aldol reaction followed by dehydration to produce cis-jasmone,a perfume component.Draw the structure of the product.

Question 30

Predict the major aldol product of the following reaction.

Question 31

Instructions: Draw the structures of the precursors to the Michael reaction products shown in the question(s)below.Label the Michael donor and the Michael acceptor in each case and formulate the reaction.

Draw and label:

Question 32

Instructions: Consider the reaction below to answer the following question(s).


Refer to instructions.This reaction is an example of:

A)a mixed Claisen condensation.
B)a Dieckman condensation.
C)a Michael reaction.
D)a mixed aldol reaction.

Question 33

Draw the structure of the diastereomer that is formed preferentially in the following reaction:

Question 34

How would you prepare the following compound using an alkylation reaction?

Question 35

Instructions: Draw the structures of the precursors to the Michael reaction products shown in the question(s)below.Label the Michael donor and the Michael acceptor in each case and formulate the reaction.

Draw and label:

Question 36

Instructions: Draw the structure of the product you would expect to obtain by Claisen condensation of the esters shown in the question(s)below.If an ester does not undergo Claisen condensation,explain why it does not.

Draw and explain:

Question 37

Instructions: Draw the structure of the product you would expect to obtain by Claisen condensation of the esters shown in the question(s)below.If an ester does not undergo Claisen condensation,explain why it does not.

Draw and explain:

Question 38

Instructions: Draw the structures of the precursors to the Michael reaction products shown in the question(s)below.Label the Michael donor and the Michael acceptor in each case and formulate the reaction.

Draw and label:

Question 39

Identify the intermediate imine that results from the following reaction.

Question 40

Identify products a and b.

Question 41

Instructions: Give the major organic product(s)of each reaction or sequences of reactions for the following question(s).Show all relevant stereochemistry.
Refer to instructions.

Question 42

Instructions: Draw the structure of the aldol self-condensation product of each compound for the following question(s).If a compound does not undergo aldol self-condensation,explain why it does not.

Draw and explain:

Question 43

Nitroethane [CH₃CH₂NO₂,pK_a = 8.6] is a much stronger acid than ethane [CH₃CH₃,pK_a » 60].Explain.

Question 44

Instructions: Consider the reaction sequence below to answer the following question(s).
Refer to instructions.Conversion of A into B is a type of reaction termed _____.

A)an acylation
B)an enolation
C)an alkylation
D)a phenylation

Question 45

Instructions: Consider the reaction sequence below to answer the following question(s).
Refer to instructions.The starting material A in this reaction sequence is called a(n)_____.

A)b-keto ester
B)a-carboethoxy ketone
C)malonic ester
D)acetoacetic ester

Question 46

Instructions: Refer to the compounds below to answer the following question(s).

Refer to instructions.Draw the structure for the enol and enolate ions corresponding to Compound I.

Question 47

Instructions: Give the major organic product(s)of each reaction or sequences of reactions for the following question(s).Show all relevant stereochemistry.

Give major product(s):

Question 48

Instructions: Refer to the compounds below to answer the following question(s).


Refer to instructions.Choose the most acidic compound from Compounds I - IV.Explain your choice.

Question 49

Instructions: Consider the structures below to answer the following question(s).
Refer to instructions.Rank the molecules above in order of increasing acidity (least acidic to most acidic).

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

Question 50

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions.Write the complete stepwise mechanism for the reaction above.Show all intermediate structures and all electron flow with arrows.

Question 51

Instructions: Draw the structure of the aldol self-condensation product of each compound for the following question(s).If a compound does not undergo aldol self-condensation,explain why it does not.

Draw and explain:

Question 52

Instructions: Refer to the compounds below to answer the following question(s).
Refer to instructions.Underline all the acidic hydrogen atoms in Compounds I through IV.

Question 53

How would you prepare 3-phenylpropanoic acid using a malonic ester synthesis?

Question 54

Instructions: Consider the structures below to answer the following question(s).

Refer to instructions.Underline the acidic hydrogen atoms in each of the molecules.

Question 55

Instructions: Consider the reaction sequence below to answer the following question(s).


Refer to instructions.Conversion of B into C involves hydrolysis of the ester followed by decarboxylation.On the structures provided below,show the electron flow for the decarboxylation step.

Question 56

Instructions: Refer to the compounds below to answer the following question(s).


Refer to instructions.Indicate which hydrogens in Compound II are the most acidic.Explain your answer.

Question 57

An enolate ion

A)is a resonance hybrid.
B)can be protonated to from the corresponding enol.
C)can be protonated to form the keto tautomer.
D)forms under basic conditions.
E)All of these

Question 58

Instructions: Draw the structure of the aldol self-condensation product of each compound for the following question(s).If a compound does not undergo aldol self-condensation,explain why it does not.

Draw and explain:

Question 59

Instructions: Give the major organic product(s)of each reaction or sequences of reactions for the following question(s).Show all relevant stereochemistry.
Give major product(s):

Question 60

How would you prepare 5-methyl-2-hexanone using an acetoacetic ester synthesis?

Question 61

Which of the following are intermediates in the acid catalyzed aldol reaction of propanal to form 2-methyl-pent-2-enal?

A)only 1 and 2
B)only 1,3 and 4
C)only 2,3 and 4
D)1,2,3 and 4

Question 62

Which of the following does not possess an enol form? Explain your choice.

Question 63

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions.Draw the structure of the enolate ion that is generated during the course of this reaction.

Question 64

Rank the following hydrogens in terms of decreasing acidity (most acidic > least acidic):

Question 65

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions.This reaction is an example of:

A)a mixed Claisen condensation.
B)a Dieckman condensation.
C)a Michael reaction.
D)a mixed aldol reaction.

Question 66

Instructions: Draw the structures of the precursors to the Michael reaction products shown in the question(s)below.Label the Michael donor and the Michael acceptor in each case and formulate the reaction.

Draw and label:

Question 67

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions.The product of this reaction is:

A)a b,g-unsaturated aldehyde
B)an a,b-unsaturated ketone
C)an a,b-unsaturated aldehyde
D)an enol

Question 68

Instructions: Draw the structure of the product you would expect to obtain by Claisen condensation of the esters shown in the question(s)below.If an ester does not undergo Claisen condensation,explain why it does not.

Draw and explain:

Question 69

Identify products a and b.

Question 70

Instructions: Draw the structures of the precursors to the Michael reaction products shown in the question(s)below.Label the Michael donor and the Michael acceptor in each case and formulate the reaction.

Draw and label:

Question 71

Instructions: Consider the reaction below to answer the following question(s).

Refer to instructions.Which carbonyl compound functions as the electrophile in this reaction?

A)A
B)B
C)C

Question 72

Instructions: Consider the reaction below to answer the following question(s).
Refer to instructions.This reaction is an example of:

A)an intramolecular Claisen condensation
B)an intramolecular aldol condensation
C)a Robinson annulation
D)a Michael reaction

Question 73

Instructions: Draw the structure of the product you would expect to obtain by Claisen condensation of the esters shown in the question(s)below.If an ester does not undergo Claisen condensation,explain why it does not.

Draw and explain:

Question 74

Instructions: Draw the structures of the precursors to the Michael reaction products shown in the question(s)below.Label the Michael donor and the Michael acceptor in each case and formulate the reaction.

Draw and label:

Question 75

Draw the structure of the diastereomer that is formed preferentially in the following reaction:

Question 76

Instructions: Each of the following compounds in the following question(s)can be prepared by a mixed aldol condensation reaction.
a)Give the structures of the aldehyde and/or ketone precursors for each aldol condensation product and formulate the reaction.
b)Give the structure of the intermediate aldol product.
Refer to instructions.Use the following compound:

Question 77

Instructions: Each of the following compounds in the following question(s)can be prepared by a mixed aldol condensation reaction.
a)Give the structures of the aldehyde and/or ketone precursors for each aldol condensation product and formulate the reaction.
b)Give the structure of the intermediate aldol product.
Refer to instructions.Use the following compound:

Question 78

Instructions: Each of the following compounds in the following question(s)can be prepared by a mixed aldol condensation reaction.
a)Give the structures of the aldehyde and/or ketone precursors for each aldol condensation product and formulate the reaction.
b)Give the structure of the intermediate aldol product.
Refer to instructions.Use the following compound:

Question 79

How many different aldols (b-hydroxyaldehydes),including constitutional isomers and stereoisomers,are formed upon treatment of butanal with base?

A)1
B)2
C)3
D)4

Question 80

Instructions: The Stork enamine reaction is a variation on the Michael reaction that utilizes an enamine nucleophile.Use this information to answer the following question.

Refer to instructions.Draw the structures of the ketone and amine products of this reaction.