Q: Which of the following correctly ranks the reactivity of carboxylic acid derivatives toward nucleophilic acyl substitution, from most reactive to least reactive?

$$\text{Acid chloride} \u003e \text{Anhydride} \u003e \text{Ester} \u003e \text{Amide} \u003e \text{Carboxylate}$$

Question 1

Which of the following correctly ranks the reactivity of carboxylic acid derivatives toward nucleophilic acyl substitution, from most reactive to least reactive?

Accepted Answer

$$	ext{Acid chloride} \u003e 	ext{Anhydride} \u003e 	ext{Ester} \u003e 	ext{Amide} \u003e 	ext{Carboxylate}$$

Question 2

What is the major organic product when acetyl chloride ($$\mathrm{CH_3COCl}) is $$treated with excess water?

Accepted Answer

$$\mathrm{CH_3COOH} ($$acetic acid)

Question 3

Which of the following best describes the mechanism of nucleophilic acyl substitution for acid chlorides?

Accepted Answer

Addition of nucleophile to the carbonyl carbon forms a tetrahedral intermediate, followed by elimination of chloride ion.

Question 4

Which reagent is commonly used to convert a carboxylic acid to an acid chloride?

Accepted Answer

$$\mathrm{$$SOCl_2$$} ($$thionyl chloride)

Question 5

Which of the following carboxylic acid derivatives is the least reactive toward hydrolysis under both acidic and basic conditions?

Accepted Answer

Amide

Question 6

In the base-catalyzed hydrolysis (saponification) of an ester, what is the final organic product after acid workup?

Accepted Answer

Carboxylic acid

Question 7

Which of the following statements about keto-enol tautomerism is correct?

Accepted Answer

The alpha hydrogen of a carbonyl compound is more acidic than a typical sp$$^3 C-H $$bond.

Question 8

Which base is commonly used to generate the enolate ion quantitatively from a ketone?

Accepted Answer

$$\mathrm{LDA} ($$lithium diisopropylamide)

Question 9

Which of the following is a key step in the mechanism of the aldol condensation?

Accepted Answer

Formation of an enolate ion, which attacks another carbonyl compound.

Question 10

What is the product of the Dieckmann cyclization?

Accepted Answer

A cyclic beta-keto ester

Question 11

Which of the following best describes the Michael addition?

Accepted Answer

A nucleophilic addition to the beta carbon of an alpha, beta-unsaturated carbonyl compound.

Question 12

Which nucleophile would most likely undergo 1,2-addition to an alpha, beta-unsaturated carbonyl compound?

Accepted Answer

$$\mathrm{RMgBr} ($$Grignard reagent)

Question 13

Which of the following is a correct IUPAC name for the compound with the structure $$\mathrm{ClCH_2CH_2COOH}$$?

Accepted Answer

3-chloropropanoic acid

Question 14

Which of the following statements about the Robinson annulation is correct?

Accepted Answer

It forms a six-membered ring via a Michael addition followed by an intramolecular aldol condensation.

Question 15

Which of the following is the correct order of priority for functional groups in IUPAC nomenclature (highest to lowest) among the following: carboxylic acid, ester, aldehyde, ketone?

Accepted Answer

Carboxylic acid \u003e Ester \u003e Aldehyde \u003e Ketone

Question 16

Which of the following best explains why amides are less reactive than esters toward nucleophilic acyl substitution?

Accepted Answer

The lone pair on nitrogen delocalizes into the carbonyl, stabilizing the amide and reducing electrophilicity.

Question 17

Which product is formed when a ketone with alpha hydrogens is treated with bromine in aqueous sodium hydroxide?

Accepted Answer

Alpha-brominated ketone

Question 18

Which of the following is a necessary condition to favor intramolecular aldol cyclization over intermolecular aldol condensation?

Accepted Answer

The presence of a dicarbonyl compound with a chain length suitable for 5- or 6-membered ring formation.

Question 19

Which of the following statements about enamine formation is correct?

Accepted Answer

Enamines are formed by the reaction of a secondary amine with a ketone or aldehyde.

Question 20

Which of the following best describes the product of the following reaction: $$\mathrm{CH_3COCl}$$ + $$\mathrm{CH_3OH} (in $$the presence of base)?

Accepted Answer

$$\mathrm{CH_3COOCH_3} ($$methyl acetate)

Carboxylic Acid Derivatives and Alpha Substitution Reactions: Study Notes

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