Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives

Bruice8th EditionOrganic ChemistryISBN: 9780135213711당신이 사용하는 게 아니라요?교과서 변경

Bruice 8th Edition

Ch. 16 - Reactions of Aldehydes and Ketones • More Reactions of Carboxylic Acid Derivatives

문제 58e

16장, 문제 58e

Draw the products of the following reactions. Indicate whether each reaction is an oxidation or a reduction.
e.

검증된 단계별 안내

Step 1: Analyze the given reaction. The starting material is a methyl ester (cyclohexanecarboxylic acid methyl ester), and the reagents are lithium aluminum hydride (LiAlH4) followed by acid workup (H3O+). LiAlH4 is a strong reducing agent used to reduce esters to primary alcohols.

Step 2: Understand the mechanism. LiAlH4 donates hydride ions (H-) to the carbonyl carbon of the ester, breaking the C=O bond and forming an intermediate alkoxide. The methoxy group (-OCH3) is displaced as methanol during the reaction.

Step 3: After the reduction by LiAlH4, the intermediate alkoxide is protonated during the acid workup (H3O+), resulting in the formation of a primary alcohol. The ester group is completely reduced to an alcohol.

Step 4: Identify the product. The ester group (-COOCH3) in cyclohexanecarboxylic acid methyl ester is reduced to a primary alcohol (-CH2OH), resulting in cyclohexanemethanol as the product.

Step 5: Classify the reaction. Since the reaction involves the addition of hydrogen (reduction of the ester to an alcohol), it is classified as a reduction reaction.

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.

Reduction Reactions

Reduction reactions involve the gain of electrons or hydrogen, or the loss of oxygen by a molecule. In organic chemistry, this often pertains to the conversion of carbonyl compounds (like aldehydes and ketones) into alcohols. The reaction shown in the image illustrates the reduction of a carbonyl compound using lithium aluminum hydride (LiAlH4), a strong reducing agent.

Lithium Aluminum Hydride (LiAlH4)

Lithium aluminum hydride is a powerful reducing agent commonly used in organic synthesis. It can reduce a variety of functional groups, including carbonyls and esters, to their corresponding alcohols. In the reaction depicted, LiAlH4 donates hydride ions (H-) to the carbonyl carbon, facilitating the reduction process.

Protonation of Alkoxides

After the reduction step, the alkoxide intermediate formed needs to be protonated to yield the final alcohol product. This is typically achieved by adding a proton source, such as water or an acid, as shown in the second step of the reaction. This step is crucial as it converts the alkoxide into a stable alcohol, completing the reduction process.

Draw the products of the following reactions. Indicate whether each reaction is an oxidation or a reduction. e.