Which of the following on treatment with hot concentrated acidified `KMnO_4` gives 2 - methylhexane -1,6 - dioic acid the only organic product ?

Options

A.
B.
C.
D.

Answer

To solve the question, we need to identify which compound, when treated with hot concentrated acidified KMnO4, will yield 2-methylhexane-1,6-dioic acid as the only organic product.

### Step-by-Step Solution:

1. **Understand the Reaction**: Hot concentrated acidified KMnO4 is a strong oxidizing agent that performs oxidative cleavage of alkenes. This means that it will break the double bonds in alkenes and convert them into carbonyl compounds (aldehydes or ketones), which can further oxidize to carboxylic acids.

2. **Identify the Target Product**: The target product is 2-methylhexane-1,6-dioic acid. This compound has a six-carbon chain (hexane) with two carboxylic acid (-COOH) groups at the 1 and 6 positions, and a methyl group at the 2 position.

3. **Determine the Structure of the Starting Material**: To produce 2-methylhexane-1,6-dioic acid, we need a compound that, upon oxidative cleavage, will yield the necessary carbon skeleton. The presence of a double bond in the starting material is crucial.

4. **Consider Possible Alkenes**: We need to analyze the possible alkenes that can lead to the desired product. The structure of 2-methylhexane-1,6-dioic acid suggests that the starting alkene should have a double bond that, when cleaved, will yield the two ends that can be oxidized to form the carboxylic acids.

5. **Perform the Cleavage Reaction**:
- For a hypothetical alkene, say 2-methyl-2-hexene, upon treatment with KMnO4, the double bond between the second and third carbon will cleave.
- This cleavage will yield two carbon fragments: one end will be oxidized to form a carboxylic acid at carbon 1, and the other end will be oxidized to form a carboxylic acid at carbon 6.

6. **Verify the Product**: After the oxidative cleavage, we should verify that the resulting fragments correspond to the structure of 2-methylhexane-1,6-dioic acid. The resulting structure should have:
- A carboxylic acid group at the 1st carbon.
- A methyl group on the 2nd carbon.
- A carboxylic acid group at the 6th carbon.

7. **Conclusion**: The alkene that meets these criteria will yield 2-methylhexane-1,6-dioic acid as the only organic product upon treatment with hot concentrated acidified KMnO4.