Deck 20: Introduction to Carbonyl Chemistry;

Question 1

What is the product of the following reaction?

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

Answer 1

III

Question 2

Which reagent can be used to reduce the alkene in cyclopentenone?

A)NaBH₄
B)LiAlH₄
C)H₂ and Pd-C
D)DIBAL-H

Answer 2

H₂ and Pd-C

Question 3

Why would the alcohol in the following compound need to be protected before reaction?

A)If it isn't protected, the product will be a carboxylic acid.
B)The Grignard reagent will react with the alcohol before the ketone.
C)Magnesium is Lewis acidic and will coordinate with the alcohol.
D)There is no need to protect the alcohol.

Answer 3

The Grignard reagent will react with the alcohol before the ketone.

Question 4

What reagent can be used to cleave a silyl ether protecting group?

A)NaOMe
B)MeMgBr
C)Bu₄NF
D)Pd/C

Question 5

What is the product of the following reaction?

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

Question 6

What will be the product of the following reaction (before any aqueous work-up)?

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

Question 7

What is the major organic product in the following sequence of reactions?

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

Question 8

What is the major organic product of the following reaction?

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

Question 9

What is the product of the following reaction?

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

Question 10

What is the major organic product of the following reaction?

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

Question 11

What is the purpose of a silyl ether?

A)To protect esters from organometallic reagents and other reagents
B)To protect ketones from organometallic reagents and other reagents
C)To protect alcohols from organometallic reagents and other reagents
D)To prevent the formation of carboxylic acids

Question 12

What is the major organic product of the following reaction?

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

Question 13

Why are ketones less reactive than aldehydes?

A)Ketones are more sterically hindered.
B)Ketones are less electron deficient due to donation from the two alkyl groups.
C)The statement is false; ketones are more reactive than aldehydes.
D)Both (a) Ketones are more sterically hindered and (b) Ketones are less electron deficient due to donation from the two alkyl groups.

Question 14

What is the product of the following reaction?

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

Question 15

What is the product of the following reaction?

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

Question 16

Which reagent can be used to reduce an acid chloride to an aldehyde?

A)NaBH₄
B)LiAlH(OtBu)₃
C)LiAlH₄
D)FeCl₃

Question 17

What is the name of the general reaction type that aldehydes and ketones undergo?

A)Electrophilic addition
B)Nucleophilic addition
C)Nucleophilic substitution
D)Electrophilic substitution

Question 18

What reagent would be used to reduce an amide to an amine?

A)NaBH₄
B)LiAlH(OtBu)₃
C)LiAlH₄
D)FeCl₃

Question 19

Which reagent can be used to reduce the carbonyl in methyl vinyl ketone?

A)NaBH₄/CH₃OH
B)H₂ and Pd-C
C)FeCl₃
D)NaH

Question 20

What is the product of the following reaction?

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

Question 21

If the starting material has no stereogenic centers, when carbonyl compounds are reduced with a reagent such as LiAlH₄ or NaBH₄ and a new stereogenic center is formed, what will the composition of the product mixture be?

A)Forms a racemic mixture of the two possible enantiomers
B)Forms more of one enantiomer than another because of steric reactions around the carbonyl
C)Forms more of one enantiomer than another depending on the temperature of the reaction
D)Forms different products depending on the solvent used

Question 22

What is the major organic product of the following reaction?

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

Question 23

What is the starting material in the reaction below?

A)Bromobenzene
B)Benzyl bromide
C)Benzoic acid
D)Lithium benzoate

Question 24

What is the missing reagent in the reaction below?

A)PhMgBr then H₂O
B)Benzene, AlCl₃
C)Ph₂CuLi then H₂O
D)PhLi then H₂O

Question 25

What is the missing reagent in the reaction below?

A)NaBH₄/CH₃OH
B)H₂, Pd-C
C)LiAlH₄ then H₂O
D)MeMgBr then H₂O

Question 26

What is the missing reagent in the reaction below?

A)[1] LiAlH₄, [2] H₂O
B)[1] CH₂=CHLi, [2] H₂O
C)[1] (CH₂=CH)₂CuLi, [2] H₂O
D)[1] DIBAL-H, [2] H₂O

Question 27

Both LiAlH₄ and NaBH₄ are reducing agents.Which statement about these reagents is true?

A)Both reagents contain polar metal-hydrogen bonds.The polarity of the B-H bond is greater than the polarity of the Al-H bond, so LiAlH₄ is the stronger reducing agent.
B)Both reagents contain polar metal-hydrogen bonds.The polarity of the B-H bond is greater than the polarity of the Al-H bond, so LiAlH₄ is the weaker reducing agent.
C)Both reagents contain polar metal-hydrogen bonds.The polarity of the B-H bond is less than the polarity of the Al-H bond, so LiAlH₄ is the stronger reducing agent.
D)Both reagents contain polar metal-hydrogen bonds.The polarity of the B-H bond is less than the polarity of the Al-H bond, so LiAlH₄ is the weaker reducing agent.

Question 28

What is the missing reagent in the reaction below?

A)[1] LiAlH₄, [2] H₂O
B)[1] CH₃MgBr (excess), [2] H₂O
C)[1] (CH₃)₂CuLi (excess), [2] H₂O
D)[1] DIBAL-H, [2] H₂O

Question 29

A carbonyl group, C=O, and an alkene, C=C, double bonds are both sp2 hybridized.However, the chemistry of These two functional groups is very different.This can be explained by which of the following statements?

A)The bond angle of the carbonyl is larger than the bond angle of the alkene.
B)The electronegative oxygen of the C=O group makes this bond polar.
C)The bond of the C=C is longer that the bond of the C=O.
D)There is more steric crowding in the carbonyl than in the alkene.