Deck 12: Introduction to Carbonyl Chemistry; Organometallic Reagents; Oxidation and Reduction

Question 1

What is the product of the following reaction?

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

Answer 1

II

Question 2

What is the product of the following reaction?

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

Answer 2

III

Question 3

The reduction of 2-butanone with sodium borohydride will result in a product with the following type of stereochemistry:

A) An enantiomeric excess of one enantiomer
B) A meso compound
C) A mix of diastereomers
D) A racemic mixture

Answer 3

A racemic mixture

Question 4

What is the product of the following reaction?

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

Question 5

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 different products depending on the solvent used
C) Forms more of one enantiomer than another depending on the temperature of the reaction
D) Forms more of one enantiomer than another because of steric reactions around the carbonyl

Question 6

What is the product of the following reaction?

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

Question 7

What is the missing reagent in the reaction below?

A) LiAlH₄
B) [1] Mg, [2] CO₂, [3] acidic work-up
C) [1] CO₂, [2] acidic work-up
D) [1] CO₂, [2] NaOH

Question 8

What is the product of the following reaction?

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

Question 9

What is the product of the following reaction?

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

Question 10

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 less 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 greater 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 11

What is the starting material in the reaction below?

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

Question 12

A carbonyl group, C=O, and an alkene, C=C, double bonds are bothsp² hybridized. However, the chemistry of these two functional groups is very different. This can be explained by which of the following statements?

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

Question 13

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

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

Question 14

What is the missing reagent in the reaction below?

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