Which reagent is used to perform base hydrolysis of esters (saponification)?

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Multiple Choice

Which reagent is used to perform base hydrolysis of esters (saponification)?

Base hydrolysis of esters, or saponification, uses hydroxide to attack the carbonyl carbon of the ester. The hydroxide ion is a strong nucleophile that adds to the carbonyl, forming a tetrahedral intermediate. This intermediate collapses and ejects the alkoxide, giving a carboxylate species. In basic solution, that carboxylate remains as a salt (carboxylate ion), while the alkoxy group becomes the corresponding alcohol after proton transfer. Because the reaction is driven by forming a stable carboxylate salt, it proceeds readily with a strong base like sodium hydroxide. Other options don’t fit base hydrolysis: a strong acid like hydroiodic acid would promote acid-catalyzed hydrolysis rather than base hydrolysis; pyridinium chlorochromate is an oxidizing agent for alcohols, not for hydrolysis; phosphoric acid is an acid catalyst, not a base.

Base hydrolysis of esters, or saponification, uses hydroxide to attack the carbonyl carbon of the ester. The hydroxide ion is a strong nucleophile that adds to the carbonyl, forming a tetrahedral intermediate. This intermediate collapses and ejects the alkoxide, giving a carboxylate species. In basic solution, that carboxylate remains as a salt (carboxylate ion), while the alkoxy group becomes the corresponding alcohol after proton transfer. Because the reaction is driven by forming a stable carboxylate salt, it proceeds readily with a strong base like sodium hydroxide.

Other options don’t fit base hydrolysis: a strong acid like hydroiodic acid would promote acid-catalyzed hydrolysis rather than base hydrolysis; pyridinium chlorochromate is an oxidizing agent for alcohols, not for hydrolysis; phosphoric acid is an acid catalyst, not a base.

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