Quiz - Carboxylic Acid Derivatives | Carboxylic Acid Derivatives - Part 1

1

What is the order of reactivity of the carboxylic acid derivatives from the least reactive to the most reactive?

Carboxylic anhydrides < esters < amides < acyl halides

Esters < amides < acyl halides < carboxylic anhydrides

Amides < esters < carboxylic anhydrides < acyl halides

Acyl halides < carboxylic anhydrides < esters < amides

2

Which carboxylic acid derivative has the most acidic proton on the α-carbon?

Ester

Amide

Carboxylic anhydride

Acyl halide

The pKa of hydrogens on the α-carbon depends on the electronegativity of the group attached to the C=O bond ⇒ the lower the electronegativity, the higher the pKa. Acyl halide: pKa ~ 16; Carboxylic anhydride: pKa ~ 20; Ester: pKa ~ 25; Amide: pKa ~ 30

3

What is the typical chemical reaction of carboxylic acid derivatives?

Substitution nucleophile

Addition - elimination

Reduction

Oxidation

4

Which of the following reagents converts an ester to an aldehyde?

DIBAL-H

CH3MgBr

LiAlH4

NaOH / H2O

5

What are the starting reagents of a transesterification?

2 esters

Carboxylic acid + ester

Carboxylic acid + alcohol

Ester + alcohol

Mechanism of transesterification:

6

Which of the following reagents converts an amide to an amine?

DIBAL-H

CH3MgBr

LiAlH4

H2SO4 / H2O