Question

Rank the following amides from greatest reactivity to least reactivity toward acid-catalyzed hydrolysis:

Accepted Answer

Step 1: Understand the mechanism of acid-catalyzed hydrolysis of amides. Acid-catalyzed hydrolysis involves protonation of the amide carbonyl group, making it more electrophilic and susceptible to nucleophilic attack by water. The reactivity of the amide depends on the electronic effects of substituents attached to the nitrogen or the carbonyl group. Step 2: Analyze the substituents on the amides. In structure A, the substituent is a cyclohexyl group, which is non-aromatic and does not have significant electron-withdrawing or donating effects. In structure B, the substituent is a nitro group (-NO₂) attached to a benzene ring, which is strongly electron-withdrawing and increases the electrophilicity of the carbonyl group. In structure C, the substituent is a methyl group (-CH₃) attached to a benzene ring, which is weakly electron-donating and decreases the electrophilicity of the carbonyl group. Step 3: Rank the substituents based on their electronic effects. Electron-withdrawing groups like the nitro group in structure B increase the reactivity of the amide toward hydrolysis, while electron-donating groups like the methyl group in structure C decrease the reactivity. The cyclohexyl group in structure A has a neutral effect compared to the other two. Step 4: Consider the resonance effects of the aromatic substituents. In structure B, the nitro group can withdraw electron density from the benzene ring through resonance, further increasing the electrophilicity of the carbonyl group. In structure C, the methyl group can donate electron density to the benzene ring through hyperconjugation, reducing the electrophilicity of the carbonyl group. Step 5: Rank the amides from greatest reactivity to least reactivity based on the analysis. Structure B (with the nitro group) is the most reactive due to the strong electron-withdrawing effect. Structure A (with the cyclohexyl group) is moderately reactive due to the lack of significant electronic effects. Structure C (with the methyl group) is the least reactive due to the electron-donating effect.

Rank the following amides from greatest reactivity to least reactivity toward acid-catalyzed hydrolysis:

비슷한 문제에 대한 검증된 영상 답변:

주요 개념

Amide Reactivity

Electronic Effects

Acid-Catalyzed Hydrolysis