Understanding the Reaction of n-Butyl Bromide with Aqueous KOH: Structure and Naming of the Chief Organic Product

Understanding the reaction of n-butyl bromide (CH?CH?CH?CH?Br) with aqueous potassium hydroxide (KOH) involves comprehending the mechanism, structure, and naming of the chief organic product. This process typically follows a nucleophilic substitution reaction (SN2) mechanism, leading to the formation of n-butanol.

Reaction Overview

Nucleophile: The hydroxide ion (OH-) from KOH acts as the nucleophile.

Leaving Group: The bromide ion (Br-) leaves the molecule as the nucleophile attacks the carbon atom bonded to the bromine.

The overall reaction can be written as:

CH?CH?CH?CH?Br KOH rarr; CH?CH?CH?CH?OH KBr

Structure of n-Butanol

n-Butanol has the following structural formula:

The formula for n-butanol is:

CH?CH?CH?CH?OH

IUPAC Name

The IUPAC name for n-butanol is:

Butan-1-ol

Reaction Mechanism

The reaction mechanism follows a nucleophilic substitution reaction (SN2). Here's a step-by-step explanation:

The hydroxide ion, acting as the nucleophile, approaches the carbon atom bonded to the bromine. The bromide ion, as a good leaving group, departs, transferring the negative charge to the carbon atom. The resulting carbocation undergoes a backside attack by the incoming hydroxide ion, leading to the formation of n-butanol.

This reaction is also known as a nucleophilic substitution reaction (SN2).

Summary

The chief organic product expected from the reaction of n-butyl bromide with aqueous KOH is n-butanol (butan-1-ol).

Additional Insights

It's important to note that while n-butanol is the chief product, other minor products can also be formed, such as 2-buten-1-ol through the abstraction of the beta hydrogen from the butyl molecule. This abstraction forms a double bond, and K gets Br because its bond has been weakened as a good leaving group. However, 2-buten-1-ol is a minor product in comparison to n-butanol.

The reactions leading to n-butanol and 2-buten-1-ol can be summarized as:

N-Butanol: CH?CH?CH?CH?Br KOH rarr; CH?CH?CH?CH?OH KBr 2-Buten-1-ol: (Minor Product) CH?CHCHCH?Br KOH rarr; CH?CHCHCH?OH KBr

These reactions highlight the complexity and versatility of nucleophilic substitution reactions, making them a fundamental aspect of organic chemistry.