Phenol oxidation can be coupled with other reactions to form new C―C bonds using reactions studied previously. Predict the product of the following series of reactions.
(b)

Verified step by step guidance

1. Step 1: Analyze the starting material, which is 1,2-dihydroxybenzene (catechol). The structure has two hydroxyl groups attached to a benzene ring.
2. Step 2: The first reagent, H₂CrO₄ (chromic acid), is a strong oxidizing agent. It will oxidize the catechol to form a quinone structure. This involves the conversion of the hydroxyl groups to carbonyl groups, resulting in a 1,2-benzoquinone.
3. Step 3: The second reagent is a lithium diisopropylcuprate (CuLi), which is a Gilman reagent. Gilman reagents are used for conjugate addition reactions. The 1,2-benzoquinone formed in the previous step can undergo a conjugate addition with the Gilman reagent, forming a new C-C bond.
4. Step 4: The third step involves quenching the reaction with H₃O⁺ (acidic workup). This step is typically used to neutralize the reaction mixture and can also help in protonating any intermediate alkoxide ions formed during the reaction.
5. Step 5: Consider the overall transformation: starting from catechol, oxidizing to quinone, and then forming a new C-C bond through conjugate addition. The final product will have the new alkyl group added to the quinone structure.

Key Concepts

Phenol Structure and Reactivity

Phenol is an aromatic compound with a hydroxyl (-OH) group attached to a benzene ring. Its structure allows for unique reactivity, particularly in electrophilic aromatic substitution and oxidation reactions. Understanding how the hydroxyl group influences the electron density of the aromatic ring is crucial for predicting the outcomes of reactions involving phenol.

Oxidation Reactions

Oxidation reactions involve the loss of electrons or an increase in oxidation state, often resulting in the formation of new functional groups. In the context of phenol, oxidation can lead to the formation of quinones, which are highly reactive and can participate in further reactions, including coupling with other substrates to form new carbon-carbon bonds.

C―C Bond Formation

C―C bond formation is a fundamental aspect of organic synthesis, allowing for the construction of complex molecules. Various methods, such as cross-coupling reactions and nucleophilic additions, can be employed to create these bonds. Understanding the mechanisms and conditions under which these reactions occur is essential for predicting the products of reactions involving phenol and its oxidized derivatives.