Deck 17: Carbonyl-Based Nucleophiles

Question 1

Which of the following represents a mechanistic step in the crossed aldol condensation shown below?

A)
B)
C)
D)

Answer 1

Question 2

Which of the following represents the most stable enolate?

A)
B)
C)
D)

Answer 2

Question 3

Which of the following bases would result in quantitative deprotonation of the ketone shown below?

A)NaOEt
B)NaOH
C)KOtBu
D)LDA

Answer 3

LDA

Question 4

What is the major product of the following reaction?

A)
B)
C)
D)

Question 5

What is the major product of the following reaction?

A)
B)
C)
D)

Question 6

Which order of reagents will best result in the product shown below?

A)1)KOtBu 2)BuBr 3)KOtMe 4)MeBr
B)1)KOtBu 2)MeBr 3)KOMe 4)BuBr
C)1)KOMe 2)BuBr 3)KOtBu 4)MeBr
D)1)KOMe 2)MeBr 3)KOtBu 4)BuBr

Question 7

Which of the following represents the most stable enolate structure?

A)
B)
C)
D)

Question 8

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

A)
B)
C)
D)

Question 9

Which of the following represents the most reactive enolate?

A)
B)
C)
D)

Question 10

What is the following molecule?

A)ylide
B)phosphane
C)phosphate
D)haloform

Question 11

Which of the following best describes the molecules shown in the equilibrium below?

A)I and IV are tautomers.
B)I and IV are tautomers,and II and III are tautomers.
C)I and II are tautomers.
D)I and IV are tautomers,and III and IV are tautomers.

Question 12

Which of the following is an intermediate of the reaction shown below?

A)
B)
C)
D)

Question 13

What is the major product of the reaction shown below?

A)
B)
C)
D)

Question 14

What is the major product of the following reaction?

A)
B)
C)
D)

Question 15

Which of the following represents the most stable enolate?

A)
B)
C)
D)

Question 16

What it the major product of the reaction shown below?

A)
B)
C)
D)

Question 17

Which of the following best describes the aldol reaction?

A)Carbonyls and enolates act as nucleophiles.
B)Carbonyls and enolates act as electrophiles.
C)Carbonyls act as nucleophiles;enolates act as electrophiles.
D)Carbonyls act as electrophiles;enolates act as nucleophiles.

Question 18

What is the major product of the following reaction?

A)
B)
C)
D)

Question 19

What is the product of the following reaction?

A)
B)
C)
D)

Question 20

Which of the following compounds is the most acidic?

A)
B)
C)
D)

Question 21

What are the products of the Wittig reaction?

A)triphenyl phosphate and an alkene with Z stereochemistry
B)triphenyl phosphine and an alkene with Z stereochemistry
C)triphenyl phosphate and an alkene with E stereochemistry
D)triphenyl phosphine and an alkene with E stereochemistry

Question 22

What is the major product of the following reaction conditions?

A)
B)
C)
D)

Question 23

What phosphite reactant is responsible for formation for the following product when reacted with a ketone?

A)
B)
C)
D)

Question 24

Which of the following is the enamine intermediate of the reaction shown below?

A)
B)
C)
D)

Question 25

Which phosphane is responsible for the following transformation?

A)
B)
C)
D)

Question 26

What is the major product of the following reaction conditions?

A)
B)
C)
D)

Question 27

What functional groups are involved in a Claisen condensation?

A)two ketones
B)a ketone and an ester
C)an aldehyde and an ester
D)two esters

Question 28

What is the product of the following reaction scheme?

A)
B)
C)
D)

Question 29

How many aldol products are possible from the following reaction mixture?

A)1
B)2
C)4
D)6

Question 30

What is the role of n-BuLi in the following reaction?

A)to deprotonate the phosponium salt and create a ylide
B)to deprotonate the ketone and create an enolate
C)to act as a Grignard and nucleophilically attack the carbonyl
D)to stabilize the phosphorous-oxygen interaction

Question 31

Which of the following pairs of molecules represent tautomers?

A)
B)
C)
D)

Question 32

What is the product of the following transformation?

A)
B)
C)
D)

Question 33

What is the product of the following transformation?

A)
B)
C)
D)

Question 34

What is the product of the following transformation?

A)
B)
C)
D)

Question 35

What best describes the product of a Claisen condensation?

A)á,ä-unsaturated ester
B)â-ketoester
C)â-hydroxyester
D)á,ä-unsaturated carbonyl

Question 36

What reagent or reagents will achieve the following transformation?

A)NaOH,heat
B)1)MeMgBr 2)H₃O⁺
C)PPh₃,BuLi
D)NaBH₃

Question 37

What is the intermediate enamine in the following reaction scheme?

A)a nucleophile
B)an electrophile
C)an acid
D)a base

Question 38

Which of the following compounds has the highest pK_a?

A)
B)
C)
D)

Question 39

How many aldol products are possible from the following reaction mixture?

A)1
B)2
C)4
D)8

Question 40

Which of the following is a synthetic equivalent for the synthon shown below?

A)
B)
C)
D)

Question 41

Imines and enamines are tautomers of each other

Question 42

Claisen condensation results in a â-ketoester.

Question 43

The á proton of a ketone is more acidic then the á proton of an ester.

Question 44

The Mannich reaction involves an amine,an aldehyde,and a ketone.

Question 45

Use of a strong base in aprotic solvents promotes â elimination in the aldol reaction.

Question 46

The á proton of an aldehyde is more acidic than the á proton of a ketone

Question 47

In an intramolecular aldol reaction,the larger the ring,the faster the rate of formation.

Question 48

Tautomerization is the conversion of one compound to another through the movement of electrons

Question 49

Enolates act as nucleophiles.

Question 50

The E isomer is favoured in the Wittig reaction.

Question 51

Ylides and phosphanes are resonance forms of each other.

Question 52

Enamines act as electrophiles.

Question 53

The acid catalyzed aldol reaction promotes enone formation.

Question 54

Claisen condensation is the aldol reaction of two esters.

Question 55

A ylide contains a phosphorous carbon double bond.

Question 56

The rate-determining step of an E1_cb elimination is the deprotonation step.

Question 57

Nitriles act as nucleophiles.

Question 58

The á proton of a ketone is more acidic then the á proton of an aldehyde.

Question 59

The Wittig reaction involves transformation of a carbonyl to a ketone.

Question 60

In the Mannich reaction,the formed imine acts as a nucleophile .

Question 61

Draw the three possible cyclic products of the following reaction scheme.Which is expected to be the major product and why?

Question 62

The relationship between a ketone and an enol is referred to as _______________ .

Question 63

Draw the mechanism of the following transformation.

Question 64

Condensation of a secondary amine with a ketone results in a(n)_______________ .

Question 65

Identify the reactants of the following crossed aldol reaction.Propose a reaction scheme that would accomplish the following transformation.

Question 66

The final elimination step in the aldol reaction has a(n)_______________ mechanism.

Question 67

What is the product and mechanism of the self-condensation of ethylproponate under basic conditions (shown below)?

Question 68

The product of a Claisen self-condensation of an ester is a(n)_______________

Question 69

Acid acts as a(n)_______________ in the aldol reaction.

Question 70

The Wittig reaction favours the _______________ isomer.

Question 71

Compounds containing _______________ groups are capable of decarboxylation.

Question 72

The final elimination step in the aldol reaction results in a(n)_______________ .

Question 73

Propose a synthetic scheme for the following transformation and propose a mechanism of the reaction shown below under basic conditions and heat present.

Question 74

The Mannich reaction results in a(n)_______________ .

Question 75

Determine the major product of the following mechanism,and draw a mechanism of the transformation.

Question 76

What is the product of the following reaction scheme?

Question 77

The Wittig reaction involves a zwitterionic phosphorous compound known asa(n)_______________ .

Question 78

Propose a mechanism for the following transformation.