Predict the products and propose mechanisms for the following reactions.
(b)

검증된 단계별 안내

Step 1: Analyze the reactant structure. The given compound is an ester, specifically methyl benzoate, which contains a benzene ring attached to a carboxylic acid ester functional group (-COOCH3). The reaction conditions involve hydroxide ions (OH⁻) in water, indicating a base-catalyzed hydrolysis reaction.

Step 2: Understand the reaction mechanism. Base-catalyzed hydrolysis of esters proceeds through nucleophilic attack by the hydroxide ion (OH⁻) on the carbonyl carbon of the ester group. This forms a tetrahedral intermediate.

Step 3: Break down the intermediate. The tetrahedral intermediate collapses, leading to the cleavage of the ester bond. The methoxide ion (CH3O⁻) is expelled as a leaving group, and a carboxylate ion (-COO⁻) is formed.

Step 4: Finalize the product formation. In the aqueous environment, the carboxylate ion reacts with water to form benzoic acid (C6H5COOH) as the final product. The methoxide ion (CH3O⁻) may also react with water to form methanol (CH3OH).

Step 5: Summarize the reaction. The base-catalyzed hydrolysis of methyl benzoate under OH⁻/H2O conditions results in the formation of benzoic acid and methanol as the products.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

영상 길이:

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Saponification

Saponification is a chemical reaction that involves the hydrolysis of esters in the presence of a strong base, typically sodium hydroxide (NaOH) or potassium hydroxide (KOH). In this process, an ester reacts with hydroxide ions to produce an alcohol and a carboxylate salt. This reaction is commonly associated with the production of soap from fats and oils, where the ester bonds are broken down to yield fatty acid salts.

Mechanism of Nucleophilic Substitution

The mechanism of nucleophilic substitution involves the attack of a nucleophile on an electrophilic carbon atom, leading to the displacement of a leaving group. In the case of saponification, the hydroxide ion acts as the nucleophile, attacking the carbonyl carbon of the ester. This results in the formation of a tetrahedral intermediate, which subsequently collapses to release the alcohol and form the carboxylate ion.

Role of Hydroxide Ion

The hydroxide ion (OH-) plays a crucial role in saponification as a strong nucleophile that initiates the reaction. Its high electron density allows it to effectively attack the electrophilic carbon of the ester, facilitating the cleavage of the ester bond. The presence of water in the reaction medium also aids in the hydrolysis process, ensuring that the products are formed efficiently and that the reaction reaches completion.

Predict the products and propose mechanisms for the following reactions.(b)