Show how you would use Grignard syntheses to prepare the following alcohol from the indicated starting material and any other necessary reagents.
(g) cyclopentylphenylmethanol from benzaldehyde (Ph–CHO)

검증된 단계별 안내

Identify the target alcohol and the starting material: The target alcohol is cyclopentylphenylmethanol, and the starting material is benzaldehyde (Ph-CHO). The Grignard reagent will be used to introduce the cyclopentyl group to the benzaldehyde.

Prepare the Grignard reagent: React cyclopentyl bromide (C5H9Br) with magnesium (Mg) in anhydrous ether to form cyclopentylmagnesium bromide (C5H9MgBr). This is the nucleophilic reagent that will attack the carbonyl group of benzaldehyde.

Perform the Grignard reaction: Add the Grignard reagent (C5H9MgBr) to benzaldehyde (Ph-CHO) in an anhydrous ether solvent. The nucleophilic carbon in the Grignard reagent will attack the electrophilic carbon of the carbonyl group, forming a tetrahedral alkoxide intermediate.

Protonate the alkoxide intermediate: After the Grignard reaction, perform an acidic workup by adding a dilute acid (e.g., HCl or H2SO4) to protonate the alkoxide intermediate. This step converts the alkoxide into the desired alcohol, cyclopentylphenylmethanol.

Verify the product: Confirm the structure of the product using spectroscopic techniques such as NMR or IR to ensure that cyclopentylphenylmethanol has been successfully synthesized.

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.

Grignard Reagents

Grignard reagents are organomagnesium compounds, typically represented as R-MgX, where R is an organic group and X is a halogen. They are highly reactive and can act as nucleophiles, attacking electrophilic carbon centers in carbonyl compounds. In the context of synthesizing alcohols, Grignard reagents can react with aldehydes or ketones to form alcohols after subsequent hydrolysis.

Nucleophilic Addition

Nucleophilic addition is a fundamental reaction mechanism in organic chemistry where a nucleophile attacks an electrophilic carbon atom, leading to the formation of a new bond. In the case of Grignard synthesis, the nucleophile (Grignard reagent) adds to the carbonyl carbon of benzaldehyde, resulting in the formation of an alkoxide intermediate, which can be protonated to yield the desired alcohol.

Alcohol Formation

The formation of alcohols from carbonyl compounds involves the reduction of the carbonyl group. In the Grignard synthesis, after the nucleophilic addition of the Grignard reagent to the carbonyl carbon, the resulting alkoxide can be converted to an alcohol by adding water or an acid. This process is crucial for transforming the initial reactants into the target alcohol, cyclopentylphenylmethanol in this case.

Show how you would use Grignard syntheses to prepare the following alcohol from the indicated starting material and any other necessary reagents.(g) cyclopentylphenylmethanol from benzaldehyde (Ph–CHO)