Question

Which reactant could be combined with butanol to form butyl acetate? (A) \(\left(\mathrm{CH}_{3} \mathrm{CO}\right)_{2} \mathrm{O}\) and catalytic acid (B) \(\left(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CO}\right)_{2} \mathrm{O}\) and catalytic acid (C) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CONH}_{2}\) and catalytic acid (D) \(\mathrm{CH}_{3} \mathrm{CONH}_{2}\) and catalytic acid

Short answer

(A) \((\text{CH}_3 \text{CO})_2 \text{O}\) and catalytic acid

Step-by-step solution

Recognize the type of reaction

Butyl acetate is an ester, which is typically formed through esterification or transesterification reactions involving an alcohol and either a carboxylic acid or an acid anhydride.

Identify the structure of butyl acetate

Butyl acetate has the chemical formula \(\text{C}_4\text{H}_9\text{CO}_2\text{CH}_3\). It is formed from butanol (C₄H₉OH) and acetic acid (CH₃COOH) or acetic anhydride ((CH₃CO)₂O).

Evaluate given options

Option (A) \(\text{(CH}_3\text{CO)}_2\text{O}\) and catalytic acid fits because acetic anhydride can react with butanol in the presence of an acid catalyst to form butyl acetate. The other options involve different anhydrides or amides which are not suitable for forming butyl acetate.

Confirm correct reactant

Thus, the correct reactant that can be combined with butanol to form butyl acetate is option (A) \((\text{CH}_3 \text{CO})_2 \text{O}\) and catalytic acid.

Key concepts

acid catalysis

In chemical reactions, acid catalysis involves the use of an acid to speed up the reaction. The acid doesn’t get consumed in the reaction but helps in making the process quicker and more efficient by providing protons (H⁺ ions).
This process is particularly useful in organic reactions such as esterification.

• The acid donates a proton to the reactant, making it more reactive.
• It aids in the formation of intermediates, which proceed through the reaction pathway more quickly.

In the case of forming butyl acetate from butanol and acetic anhydride, a catalytic amount of acid is used. This not only speeds up the reaction but ensures the yield of butyl acetate is higher.

acetic anhydride

Acetic anhydride is an organic compound with the formula \(( \text{CH}_3 \text{CO})_2 \text{O}}\). It is often used in organic synthesis.

• This compound acts as a reagent in various reactions, particularly in the synthesis of esters.
• It reacts with alcohols such as butanol to form esters like butyl acetate.

Acetic anhydride is more reactive than acetic acid, making it a preferable choice in esterification reactions. It provides two acyl groups, and when combined with alcohols in the presence of an acid catalyst, it efficiently forms esters.

butyl acetate synthesis

Butyl acetate is an ester commonly used as a solvent in paints and coatings. It can be synthesized through an esterification reaction.
In this case, butyl acetate is formed by reacting butanol with acetic anhydride, using an acid catalyst.

• The reaction mechanism involves the nucleophilic attack of butanol on acetic anhydride.
• This leads to the formation of butyl acetate and acetic acid as a by-product.

This process is a typical example of synthesizing esters, showcasing how reagents, such as acetic anhydride, and catalysts work together to produce the desired ester.

organic reaction mechanisms

Understanding organic reaction mechanisms is critical in mastering chemical reactions. These mechanisms detail the step-by-step pathway a chemical reaction follows to convert reactants to products.
In the esterification of butyl acetate:

• The first step involves the protonation of butanol by the acid catalyst, making it more nucleophilic.
• The butanol attacks the carbonyl carbon of acetic anhydride, forming a tetrahedral intermediate.
• Rearrangement of this intermediate results in the formation of butyl acetate and regeneration of the acid catalyst.

These steps highlight how reactants interact, how intermediates form, and the eventual formation of the final product.