The major product formed by monobromination of methylcyclopentane is -

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Answer

To solve the question of the major product formed by monobromination of methylcyclopentane, we will follow the free radical mechanism of bromination. Here’s a step-by-step breakdown of the process:

### Step 1: Initiation
In the initiation step, bromine (Br₂) is dissociated into two bromine radicals (Br•) in the presence of heat or light. This can be represented as:
\[ \text{Br}_2 \xrightarrow{\text{light/heat}} 2 \text{Br}• \]

### Step 2: Propagation
In the propagation step, one of the bromine radicals reacts with methylcyclopentane. Methylcyclopentane has a structure with a cyclopentane ring and a methyl group attached to one of the carbons. The bromine radical abstracts a hydrogen atom from the methyl group, forming a methyl radical and hydrogen bromide (HBr):
\[ \text{Br}• + \text{C}_5\text{H}_{10}\text{CH}_3 \rightarrow \text{C}_5\text{H}_{9}• + \text{HBr} \]

The methyl radical (C₅H₉•) is stabilized by the adjacent methyl group, making it the more stable radical.

Next, the methyl radical reacts with another bromine radical:
\[ \text{C}_5\text{H}_{9}• + \text{Br}• \rightarrow \text{C}_5\text{H}_{9}\text{Br} \]

This leads to the formation of the brominated product, which is 1-bromo-2-methylcyclopentane.

### Step 3: Termination
In the termination step, two radicals can combine to form a stable product. However, in this case, we focus on the major product formed during the propagation step, which is already stable.

### Final Product
The major product formed by the monobromination of methylcyclopentane is:
**1-bromo-2-methylcyclopentane**.

### Summary
The major product from the monobromination of methylcyclopentane is 1-bromo-2-methylcyclopentane.

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