Ester Hydrolysis
Mediumchemistry
Base-catalyzed ester hydrolysis (saponification) proceeds by initial:
Select the correct option:
Solution
Incorrect! Answer:
Attack by hydroxide on carbonyl carbon
- Mechanism type: This is an Acyl Nucleophilic Substitution (BAc2).
- Step 1: The hydroxide ion (OH−), acting as a powerful nucleophile, attacks the electrophilic carbonyl Carbon atom of the ester (R−COOR′).
- Intermediate: This forms a tetrahedral intermediate where the carbonyl Carbon is now sp3 hybridized.
- Step 2: The tetrahedral intermediate collapses, reforming the C=O double bond and expelling the alkoxide ion (OR′−) as the leaving group.
- Step 3 (Irreversible): The resulting carboxylic acid immediately reacts with the hydroxide/alkoxide in the basic medium to form a carboxylate salt and an alcohol. This drive the reaction to completion.
🔒 Solution Hidden from View
Submit your answer to unlock the detailed step-by-step solution.
About This Question
- Subject
- chemistry
- Chapter
- oxygen organics
- Topic
- ester hydrolysis
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
Attack by hydroxide on carbonyl carbon
- Mechanism type: This is an Acyl Nucleophilic Substitution (BAc2).
- Step 1: The hydroxide ion (OH−), acting as a powerful nucleophile, attacks the electrophilic carbonyl Carbon atom of the ester (R−COOR′).
- Intermediate: This forms a tetrahedral intermediate where the carbonyl Carbon is now sp3 hybridized.
- Step 2: The tetrahedral intermediate collapses, reforming the C=O double bond and expelling the alkoxide ion (OR′−) as the leaving group.
- Step 3 (Irreversible): The resulting carboxylic acid immediately reacts with the hydroxide/alkoxide in the basic medium to form a carboxylate salt and an alcohol. This drive the reaction to completion.
This medium difficulty chemistry question is from the chapter oxygen organics, covering the topic of ester hydrolysis. It appeared in the 2025 exam.
Looking for more practice? Explore all chemistry questions or browse oxygen organics questions on RankGuru.