Question

Which of following is a correct set of reactions with product Category? (A) \(\mathrm{CH}_{3}-\mathrm{CHO}+\operatorname{dil} \stackrel{\Theta}{\mathrm{O}} \mathrm{H} \longrightarrow \beta\)-hydroxy carboxyl (B) \(\mathrm{CH}_{3}-\mathrm{CO}-\mathrm{CO}-\mathrm{CH}_{3}+\stackrel{\Theta}{\mathrm{O}} \mathrm{H} \longrightarrow \alpha\)-hydroxy acid Salt (C) \(\mathrm{Ph}-\mathrm{CHO}+\operatorname{Conc} \stackrel{\ominus} \mathrm{OH} \longrightarrow\) Alcohol \& Acid Salt (D) \(\mathrm{CH}_{3} \mathrm{COOH}+\stackrel{\ominus}{\mathrm{O} H} \underset{\text { Sliyht } \mathrm{H}^{+}}{\longrightarrow} \beta\)-keto ester

Short answer

The correct set of reactions with the given product category is Option B: \(\mathrm{CH}_{3}-\mathrm{CO}-\mathrm{CO}-\mathrm{CH}_{3}+\stackrel{\Theta}{\mathrm{O}} \mathrm{H} \longrightarrow \alpha \text{-hydroxy acid Salt}\), as it involves the hydrolysis of a 1,3-diketone compound in the presence of a base, yielding an α-hydroxy acid salt product.

Step-by-step solution

Option A Analysis

Option A presents the reaction: \(\mathrm{CH}_{3}-\mathrm{CHO}+\operatorname{dil} \stackrel{\Theta}{\mathrm{O}} \mathrm{H} \longrightarrow \beta \text{-hydroxy carboxyl}\) This reaction involves the addition of a dilute base to an aldehyde. However, this reaction does not typically yield a β-hydroxy carboxyl product and thus can be ruled out.

Option B Analysis

Option B presents the reaction: \(\mathrm{CH}_{3}-\mathrm{CO}-\mathrm{CO}-\mathrm{CH}_{3}+\stackrel{\Theta}{\mathrm{O}} \mathrm{H} \longrightarrow \alpha \text{-hydroxy acid Salt}\) In this reaction, the hydrolysis of a 1,3-diketone compound takes place in the presence of a base. This reaction yields an α-hydroxy acid salt product, which corresponds to the product category mentioned. Therefore, this option appears to be correct.

Option C Analysis

Option C presents the reaction: \(\mathrm{Ph}-\mathrm{CHO}+\operatorname{Conc} \stackrel{\ominus}{\mathrm{OH}} \longrightarrow \text{Alcohol }\& \text{ Acid Salt}\) This reaction involves the addition of concentrated base to an aromatic aldehyde (Benzaldehyde). However, this reaction does not typically yield the mentioned products (Alcohol and Acid Salt). Thus, this option can be ruled out.

Option D Analysis

Option D presents the reaction: \(\mathrm{CH}_{3} \mathrm{COOH}+\stackrel{\ominus}{\mathrm{O} H} \underset{\text { Sliyht } \mathrm{H}^{+}}{\longrightarrow} \beta\text{-keto ester}\) This reaction involves the reaction of an acetic acid with a base. However, the products formed in this reaction are not consistent with the mentioned products (β-keto ester). Thus, this option can be ruled out as well. From the analysis, Option B is the correct set of reactions that match the product category stated.

Key concepts

Aldehyde Reactions

Aldehyde reactions are fundamental in organic chemistry. They often involve nucleophilic additions where a nucleophile targets the carbon in the carbonyl group of the aldehyde. When aldehydes react, the carbon-oxygen double bond is usually attacked by nucleophiles, leading to the formation of various products. Understanding these reactions is crucial as they serve as building blocks for larger molecules in numerous synthetic processes.

In the context of our exercise, we explore a scenario where an aldehyde ( \( ext{Ph-CHO}\), benzaldehyde) is treated with a concentrated base ( \( ext{OH}^{-}\)). Although benzaldehyde frequently undergoes reactions with bases to potentially form alcohols or salts, the formation of an alcohol and an acid salt as suggested in the problem is inaccurate. More commonly, aldehydes can undergo Aldol reactions where enolizable aldehydes will form a β-hydroxy aldehyde, which wasn't the correct pathway for the stated exercise.

Always remember to evaluate the functional groups present and reactants involved to determine the correct products.

Hydrolysis of Diketones

Hydrolysis of diketones encompasses the reactions where water is used to break down diketone structures, often in the presence of a catalyst. These reactions are interesting because they often lead to the formation of carboxylic acid derivatives which are pivotal in organic synthesis.

Referring to the problem at hand, the compound \( ext{CH}_{3}-\text{CO}-\text{CO}-\text{CH}_{3}\) represents a 1,3-diketone. In the presence of a base, an interesting transformation occurs where the diketone hydrolyzes to form α-hydroxy acid salts. This reaction aligns perfectly with the proposed products in option B of our solution: alpha-hydroxy acid salts.

This type of reaction is notable for the cleavage at one of the carbonyl groups, which promotes the formation of a carboxylate ion (the salt form of an acid) and a secondary alcohol (the hydroxy group). The base facilitates the initial deprotonation, making the reaction more favorable. Keeping this mechanism in mind helps to predict the outcomes of similar diketone reactants.

Base-catalyzed Reactions

Base-catalyzed reactions are a cornerstone in organic chemistry, where bases act as catalysts, promoting the deprotonation of acidic protons, usually adjacent to a carbonyl group. This typically results in the formation of reactive species like enolates, which are key intermediates in many transformation reactions.

In our exercise, the reaction using a base under dilute conditions does not favor the formation of the propose β-hydroxy carboxyl compound. Instead, many such reactions, depending on structure, result in aldol condensation or similar reactions involving the enolate ion. Conversely, in the correct example with diketones, the base assists in creating an enol or enolate, which aids hydrolysis to form an α-hydroxy acid salt.

These reactions highlight the diverse pathways and products possible when using base catalysis. Factors such as concentration, structure of reactants, and solvent all play pivotal roles in determining the reaction's outcome. By understanding the basic principles of these reactions, you can better predict and explore their outcomes in various synthetic applications.