In the given reaction ,
`overset(Br) overset(|)(CH_2)-(CH_2)_(3)-CH_2-OH underset("Toluene" 140^@C)overset(NaOH)(rarr)(X)`
X will be

Options

A. `overset(OH)overset(|)(CH_2)-(CH_2)_(4)-CH_2OH`
B. `CH_2=CH-(CH_2)_(3)-CH_2OH`
C. `CH_3-overset(OH)overset(|)(CH)-(CH_3)_(3)-CH_2OH`
D.

Answer

To solve the given reaction step by step, we will analyze the components involved and the expected reaction mechanism.

### Step 1: Identify the Reactants
The reactant is a brominated alcohol, specifically 1-bromo-3-pentanol (Br-CH2-CH2-CH2-CH2-OH). The presence of NaOH indicates that we will have a base-catalyzed reaction.

**Hint:** Look for the functional groups in the reactant to determine how they might interact with NaOH.

### Step 2: Determine the Reaction Mechanism
Since we have a primary alkyl halide (1-bromo-3-pentanol) and a strong base (NaOH), we can initially consider the possibility of an SN2 reaction. However, the presence of the hydroxyl (-OH) group introduces an acidic hydrogen that can be abstracted by the base.

**Hint:** Remember that primary halides often undergo SN2 reactions, but other factors can influence the outcome.

### Step 3: Deprotonation of the Alcohol
The hydroxide ion (OH-) from NaOH will abstract the acidic hydrogen from the hydroxyl group (-OH) of the alcohol. This results in the formation of an alkoxide ion (O-) and the corresponding bromide ion (Br-).

**Hint:** Identify the acidic hydrogen in the alcohol that can be removed by the base.

### Step 4: Formation of the Alkoxide Ion
After deprotonation, we get the alkoxide ion (O-) attached to the carbon chain. The structure can be represented as CH2-CH2-CH2-CH2-O-.

**Hint:** Visualize the structure of the alkoxide ion formed after deprotonation.

### Step 5: Nucleophilic Attack
Now, the alkoxide ion (O-) acts as a nucleophile and attacks the carbon atom bonded to the bromine (Br). This leads to the displacement of the bromine atom, forming a cyclic ether (a five-membered ring) due to the rearrangement of the carbon chain.

**Hint:** Consider how the nucleophile can attack the electrophilic carbon and what type of product this will yield.

### Step 6: Formation of the Product
The product formed is a five-membered cyclic ether, specifically 1,3-dioxane, where the oxygen from the alkoxide forms part of the ring. The final structure will be a cyclic compound with five carbon atoms and one oxygen atom.

**Hint:** Count the number of atoms in the ring and identify the final product.

### Conclusion
The product X formed from the reaction is a five-membered cyclic ether, specifically 1,3-dioxane.

**Final Answer:** X is 1,3-dioxane.

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