Question

During oxidation of ethanol by Oppeneaur oxidation, which of the following could substitute \(C\) for good yield of product? CC(=O)C(C)=O (A) CCC(C)=O (B) O=C1CCCCC1 (C) O=C1C=CCC=C1 (D)

Short answer

The correct answer is (C) \(O=C1CCCCC1\), cyclohexanone, as it can participate in the Oppenauer oxidation process and is likely to yield a stable carbonyl product with high yield.

Step-by-step solution

Understanding Oppenauer oxidation

Oppenauer oxidation is a process used to convert primary and secondary alcohols to aldehydes and ketones, respectively, with the help of an oxidizing agent. It is important to know that this oxidation favours the formation of more stable carbonyl compounds.

Identify the best substituent for carbon

We will analyze each of the given molecules (A-D) to determine which one suits the requirements of Oppenauer oxidation best: (A): \(CCC(C)=O\) This molecule is a ketone and can participate in oxidation process, but it will not yield a stable carbonyl compound, as the carbon attached to the carbonyl group is not stable. (B): \(CC(=O)C(C)=O\) This molecule is an aldehyde, which might participate in oxidation, but again it will not yield the desired stable carbonyl compound. (C): \(O=C1CCCCC1\) This molecule is a cyclic ketone, more specifically cyclohexanone. It can participate in the oxidation process and will provide a stable carbonyl compound, making it a better candidate. (D): \(O=C1C=CCC=C1\) This molecule is a cyclic ketone as well, but with a double bond, making it an aromatic ketone. It is less likely to undergo oxidation compared to cyclohexanone (C) as the aromatic ring provides extra stability to the compound, making it less reactive.

Determine the best molecule for high yield

Based on the analysis of each molecule, molecule (C) \(O=C1CCCCC1\), cyclohexanone, appears to be the best choice as it can participate in the Oppenauer oxidation process and is likely to yield a stable carbonyl product with high yield. So, the correct answer is: (C) \(O=C1CCCCC1\).

Key concepts

Oxidation of Alcohols

Oxidation of alcohols is an essential reaction in organic chemistry that transforms alcohols into carbonyl compounds. This chemical process helps in converting primary alcohols into aldehydes and secondary alcohols into ketones. During this transformation, the alcohol (an -OH group) loses hydrogen atoms while gaining an oxygen atom.

It is important to know that there are different methods to achieve this transformation. In the case of Oppenauer oxidation, the process is particularly gentle and selective, making it suitable for sensitive or complex alcohol molecules.

• Primary Alcohols: Convert to aldehydes with careful control to prevent further oxidation to carboxylic acids.
• Secondary Alcohols: Transform into ketones, which are often more stable than aldehydes.

This conversion is crucial in both laboratory syntheses and industrial applications due to the wide variety of carbonyl compounds that are valuable in creating other chemical products.

Carbonyl Compounds

Carbonyl compounds are characterized by the presence of a carbonyl group, which consists of a carbon atom double-bonded to an oxygen atom (\[ \text{C} = \text{O} \]). These compounds include both aldehydes and ketones, which are determined based on the positioning of the carbonyl group.

The significance of carbonyl compounds in organic chemistry lies in their reactivity, allowing them to undergo various chemical reactions, such as oxidation, reduction, and addition reactions.

• Aldehydes: These have the carbonyl group at the end of the carbon chain, making them more reactive in some reactions.
• Ketones: These have the carbonyl group within the carbon chain, often yielding more stable and less reactive molecules compared to aldehydes.

The properties of carbonyl compounds make them versatile intermediates in synthesizing numerous organic compounds, including pharmaceuticals, polymers, and fragrances.

Oxidizing Agents

Oxidizing agents play a pivotal role in chemical reactions by enabling the transfer of oxygen or the removal of hydrogen in various organic reactions, including oxidation of alcohols. These agents are essential for transforming alcohols into carbonyl compounds.

Not all oxidizing agents are suitable for all types of oxidation reactions, as some are too reactive, leading to further undesired transformations. Oppenauer oxidation specifically uses ketones as oxidizing agents, offering mild conditions for oxidation.

• Optimizing Oxidation: The choice of a mild oxidizing agent can prevent over-oxidation, enabling the formation of stable carbonyl compounds.
• Common Choices: In Oppenauer oxidation, cyclohexanone, for example, is an excellent choice due to its ability to provide stable carbonyl compounds with high yields.

Choosing the right oxidizing agent is crucial to ensure the success of the reaction and the stability of the resulting products.