An unknown compound decolorizes bromine in carbon tetrachloride, and it undergoes catalytic reduction to give decalin. When treated with warm, conc, potassium permangate, this compound give cis-cyclohexane-1, 2-dicaboxylic acid and oxalic acid. Possible a structure for th unknown compound is-

Options

A.
B.
C.
D.

Explanation

To determine the structure of the unknown compound based on the provided information, we will follow a step-by-step approach:

### Step 1: Analyze the given information
The unknown compound decolorizes bromine in carbon tetrachloride, indicating that it likely contains a double bond (unsaturated compound). Additionally, it undergoes catalytic reduction to yield decalin, which consists of two fused cyclohexane rings.

**Hint:** Look for compounds that are unsaturated and can form decalin upon reduction.

### Step 2: Understand the reaction with potassium permanganate
When treated with warm, concentrated potassium permanganate (KMnO4), the compound produces cis-cyclohexane-1,2-dicarboxylic acid and oxalic acid. This suggests that the compound has double bonds that can be oxidized to form carboxylic acids.

**Hint:** KMnO4 is a strong oxidizing agent that can oxidize alkenes to carboxylic acids.

### Step 3: Identify potential structures
We need to consider the possible structures of the unknown compound. Since it can decolorize bromine, it must have at least one double bond. The oxidation products indicate that the compound likely has two double bonds that can be oxidized to form the dicarboxylic acid and oxalic acid.

**Hint:** Look for structures with multiple double bonds that can lead to the formation of the required oxidation products.

### Step 4: Evaluate the compounds
We will evaluate each potential compound to see which one meets the criteria:

1. **First compound:** When oxidized, it forms only oxalic acid and does not yield the required dicarboxylic acid. Thus, it is not the unknown compound.

2. **Second compound:** Similar to the first, it does not yield the required products upon oxidation. Therefore, it is also not the unknown compound.

3. **Third compound:** This compound does not yield the required products either, as it does not lead to the formation of the dicarboxylic acid.

4. **Fourth compound:** Upon oxidation, this compound produces both cis-cyclohexane-1,2-dicarboxylic acid and oxalic acid, meeting the criteria set out in the problem.

**Hint:** Compare the products of oxidation for each compound to see which one matches the expected results.

### Step 5: Conclusion
Based on the analysis, the structure of the unknown compound is the fourth compound, as it is the only one that produces the required oxidation products when treated with KMnO4.

**Final Answer:** The possible structure for the unknown compound is the fourth compound.