Question 1

Which reagent is commonly used to convert a carboxylic acid to an acid chloride, and what is the byproduct of this reaction?

Accepted Answer

SOCl$$_2$$; SO$$_2$$ and HCl

Question 2

Which of the following statements best explains why acid chlorides are more reactive than esters in nucleophilic acyl substitution reactions?

Accepted Answer

Acid chlorides have a better leaving group (Cl$$^-) $$than esters (RO$$^-).$$

Question 3

What is the product when an acid chloride reacts with excess CH$$_3$$MgBr followed by aqueous workup?

Accepted Answer

A tertiary alcohol

Question 4

Which of the following is a necessary condition for the formation of an amide from an acid chloride and ammonia?

Accepted Answer

Two equivalents of ammonia are required: one to react with the acid chloride and one to neutralize the HCl formed.

Question 5

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

Accepted Answer

LiAlH(OtBu)$$_3$$

Question 6

Which of the following statements about the formation of esters from acid chlorides is correct?

Accepted Answer

The reaction is best performed in the presence of a base such as pyridine to neutralize the HCl byproduct.

Question 7

Which product is formed when an acid anhydride reacts with ethanol in the presence of triethylamine?

Accepted Answer

An ester and a carboxylic acid

Question 8

Which of the following best describes the outcome when an ester is treated with excess LiAlH$$_4$$ followed by aqueous workup?

Accepted Answer

A primary alcohol is formed

Question 9

Why is saponification of esters typically performed under basic conditions rather than acidic conditions?

Accepted Answer

The reaction is irreversible under basic conditions, driving the reaction to completion.

Question 10

Which of the following is a limitation of Fischer esterification for preparing esters?

Accepted Answer

It is limited to simple alcohols such as methanol, ethanol, and propanol.

Question 11

Which of the following statements about the reaction of acid chlorides with organocuprate reagents (R$$_2$$CuLi) is correct?

Accepted Answer

The reaction produces a ketone.

Question 12

Which of the following is true regarding the preparation of anhydrides from carboxylic acids?

Accepted Answer

It generally requires high heat and is limited to the formation of five- or six-membered cyclic anhydrides.

Question 13

Which of the following is a reason why acid chlorides are often used instead of anhydrides for acylation reactions?

Accepted Answer

Acid chlorides are more reactive and generally give higher yields.

Question 14

Which of the following best describes the product of the reaction between an ester and a Grignard reagent (2 equivalents) followed by aqueous workup?

Accepted Answer

A tertiary alcohol

Question 15

Which of the following is NOT a suitable nucleophile for the conversion of an acid chloride to an amide?

Accepted Answer

A tertiary amine

Question 16

Which of the following statements about the hydrolysis of esters is correct?

Accepted Answer

Hydrolysis under basic conditions is called saponification and produces a carboxylate salt and an alcohol.

Question 17

Which of the following is a correct statement about the reduction of esters?

Accepted Answer

Esters can be reduced to primary alcohols using LiAlH$$_4.$$

Question 18

Which of the following is a distinguishing feature of the Schotten-Baumann reaction for amide formation?

Accepted Answer

It uses one equivalent of amine and one equivalent of NaOH.

Question 19

Which of the following best explains why the reaction of acid chlorides with alcohols is affected by steric hindrance?

Accepted Answer

Bulky groups on either the acid chloride or the alcohol slow the reaction rate.

Acid Halides, Anhydrides, and Esters: Preparation and Reactions

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