A certain compound 'A' has a molecular formula `C_(5)H_(11)Br`. It reacts with Mg metal in anhydrous ether to form compound B which upon hydrolysis gives n-pentane when compound A was reacted with na metal in dry ether gave 4,5- dimethyl octane. What is A B and draw their structures?

Explanation

To solve the problem, we need to identify the compounds A and B based on the information given in the question. Let's break it down step by step.

### Step 1: Identify Compound A
Given the molecular formula of compound A is \( C_5H_{11}Br \). This indicates that it is a bromoalkane. The presence of bromine suggests that it is likely a primary or secondary alkyl bromide.

### Step 2: Analyze the Reaction with Magnesium
When compound A reacts with magnesium in anhydrous ether, it forms compound B. This reaction is known as the formation of a Grignard reagent. The general reaction can be represented as:
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