In the following sequence of reactions, identify the final product. Cyclopentance `overset(Cl_2//hv)rarr(I)overset(alc.KOH,Delta)rarr(II) overset((i) O_3)rarr(III)`

Options

A. pentanal
B. pentane -2- one
C. pentan -3-one
D. pentane -1,3,-dial

Answer

To solve the problem step by step, let's break down the reactions involved:

### Step 1: Chlorination of Cyclopentane
- **Reaction**: Cyclopentane (C5H10) is treated with Cl2 in the presence of light (hv).
- **Mechanism**: This reaction involves homolytic cleavage of Cl2 to form two chlorine radicals (Cl•). One of these radicals abstracts a hydrogen atom from cyclopentane, resulting in the formation of a cyclopentyl radical (C5H9•) and HCl.
- **Product**: The product after chlorination is chlorocyclopentane (C5H9Cl).

### Step 2: Elimination Reaction with Alcoholic KOH
- **Reaction**: The chlorocyclopentane (C5H9Cl) is treated with alcoholic KOH and heated (Δ).
- **Mechanism**: The alcoholic KOH acts as a base and abstracts a hydrogen atom from the carbon adjacent to the chlorine atom. This leads to the formation of a double bond (alkene) and the elimination of HCl.
- **Product**: The product after this step is cyclopentene (C5H8).

### Step 3: Ozonolysis of Cyclopentene
- **Reaction**: Cyclopentene (C5H8) is treated with ozone (O3).
- **Mechanism**: Ozonolysis involves the cleavage of the double bond in cyclopentene, resulting in the formation of carbonyl compounds (aldehydes or ketones).
- **Product**: The ozonolysis of cyclopentene will yield two molecules of an aldehyde. Specifically, it will produce pentanal (C5H10O) and another aldehyde, which can be identified as propanal (C3H6O) depending on the structure of the cyclopentene.

### Final Product
- The final product after the sequence of reactions is **pentane-1,3-dial** (C5H10O2), which contains two aldehyde groups at positions 1 and 3.

### Summary of Steps:
1. **Chlorination of Cyclopentane** → Chlorocyclopentane (C5H9Cl)
2. **Elimination with Alcoholic KOH** → Cyclopentene (C5H8)
3. **Ozonolysis** → Pentane-1,3-dial (C5H10O2)

### Final Answer:
The final product is **pentane-1,3-dial**.

---