What is the final product of following reaction ?
Isopropyl alcohol `overset((i)SOCl_2)underset((ii)Mg//"ether")to` ?
(iii) `CH_3-CHO`
(iv) `H_3O^+`
(v) `K_2Cr_2O_7//H^+`

Options

A.
B.
C.
D.

Explanation

To determine the final product of the given reaction sequence starting from isopropyl alcohol, we will go through each step methodically.

### Step 1: Conversion of Isopropyl Alcohol to Isopropyl Chloride
- **Reaction**: Isopropyl alcohol (CH₃CHOHCH₃) is treated with thionyl chloride (SOCl₂).
- **Mechanism**:
1. The alcohol group (-OH) reacts with SOCl₂, leading to the formation of isopropyl chloride (CH₃CHClCH₃) and the by-products SO₂ and HCl.

**Product after Step 1**: Isopropyl chloride (CH₃CHClCH₃)

### Step 2: Formation of Grignard Reagent
- **Reaction**: Isopropyl chloride is treated with magnesium (Mg) in dry ether.
- **Mechanism**:
1. The isopropyl chloride reacts with magnesium to form isopropyl magnesium chloride (CH₃C(CH₃)MgCl).

**Product after Step 2**: Isopropyl magnesium chloride (CH₃C(CH₃)MgCl)

### Step 3: Reaction with Acetaldehyde
- **Reaction**: The Grignard reagent (isopropyl magnesium chloride) is treated with acetaldehyde (CH₃CHO).
- **Mechanism**:
1. The nucleophilic carbon of the Grignard reagent attacks the carbonyl carbon of acetaldehyde, forming a new carbon-carbon bond.
2. This results in the formation of a tertiary alcohol after hydrolysis.

**Product after Step 3**: 2-Pentanol (CH₃C(CH₃)(CH₂OH)CH₃)

### Step 4: Hydrolysis
- **Reaction**: The product from Step 3 undergoes hydrolysis in the presence of H₃O⁺.
- **Mechanism**:
1. The Grignard reagent reacts with water, replacing the magnesium halide with a hydroxyl group (-OH).

**Product after Step 4**: 2-Pentanol (CH₃C(CH₃)(OH)CH₃)

### Step 5: Oxidation
- **Reaction**: 2-Pentanol is oxidized using potassium dichromate (K₂Cr₂O₇) in acidic conditions (H⁺).
- **Mechanism**:
1. The secondary alcohol (2-pentanol) is oxidized to a ketone (3-pentanone).

**Final Product**: 3-Pentanone (CH₃C(=O)CH₂CH₃)

### Summary of the Reaction Sequence:
1. Isopropyl alcohol (CH₃CHOHCH₃) + SOCl₂ → Isopropyl chloride (CH₃CHClCH₃)
2. Isopropyl chloride + Mg (dry ether) → Isopropyl magnesium chloride (CH₃C(CH₃)MgCl)
3. Isopropyl magnesium chloride + CH₃CHO → 2-Pentanol (CH₃C(CH₃)(OH)CH₃)
4. 2-Pentanol + H₃O⁺ → 2-Pentanol (remains the same)
5. 2-Pentanol + K₂Cr₂O₇/H⁺ → 3-Pentanone (CH₃C(=O)CH₂CH₃)

### Final Answer:
The final product of the reaction sequence is **3-Pentanone (CH₃C(=O)CH₂CH₃)**.

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