Deck 11: Carbonyl Alpha-Substitution Reactions and Condensation Reactions

Question 1

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

Answer 1

an intramolecular aldol condensation

Question 2

Give major product(s):

Answer 2

Question 3

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

Answer 3

All of these except C

Question 4

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

Question 5

Instructions: Consider the structures below to answer the following question(s).
Refer to instructions. Underline the most acidic hydrogen atoms in each of the molecules.

Question 6

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 7

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 8

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 9

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 10

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 11

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

-Refer to instructions. The product of this reaction is:

A) a $\beta$ , $\gamma$ -unsaturated aldehyde
B) an $\alpha$ , $\beta$ -unsaturated ketone
C) an $\alpha$ , $\beta$ -unsaturated aldehyde
D) an enol

Question 12

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 13

The common feature of $\alpha$ -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 14

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 15

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 16

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 17

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 18

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 19

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 20

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.
a)Give major product(s):
b)Why are two equivalents of Na⁺ OEt ^- required?

Question 21

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

Question 22

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 23

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

A)
B)
C)
D)

Question 24

Identify products a and b.

Question 25

Consider the reaction below to answer the following questions.
Refer to Instructions. On the structures provided above, draw arrows indicating elctron flow in the generation of the intermediate C.

Question 26

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

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

Question 27

Consider the reaction below to answer the following questions.
Refer to Instructions. The strongest base in the reaction is:

Question 28

Predict the major aldol product of the following reaction.

Question 29

Consider the reaction below to answer the following questions.
Refer to Instructions. The weakest acid in the reaction is:

Question 30

Write a resonance structure for the anion below.

Question 31

How would you prepare each of the following compounds using a malonic ester synthesis? Show all intermediate structures and all reagents.
Prepare:

Question 32

Write the complete stepwise mechanism for the reaction of cyclopentanone with bromine in acetic acid to give 2-bromocyclopentanone. Show all intermediate structures and all electron flow with arrows.

Question 33

Consider the reaction below to answer the following questions.
Refer to Instructions. The enolate ion in the reaction is:

Question 34

Write a resonance structure for the anion below.

Question 35

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 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

How would you prepare each of the following compounds using a malonic ester synthesis? Show all intermediate structures and all reagents.
Prepare:

Question 38

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.