An alkene of molecular formula `C_(9) H_(18)` on ozonolysis gives `2.2` dimethyl propanal and `2`- butanone, then the alkene is

Options

A. 2,2,4-trimethylhex-3-ene
B. 2,2,6-trimethylhex-3-ene
C. 2,3,4-trimethylhex-2-ene
D. 2,2,4-trimethylhex-2-ene

Answer

To solve the problem, we need to identify the alkene with the molecular formula \( C_9H_{18} \) that produces 2,2-dimethylpropanal and 2-butanone upon ozonolysis. Here’s a step-by-step solution:

### Step 1: Understand the Products of Ozonolysis
Ozonolysis of alkenes results in the cleavage of the double bond and the formation of carbonyl compounds (aldehydes or ketones). In this case, we have:
- 2,2-dimethylpropanal (an aldehyde)
- 2-butanone (a ketone)

### Step 2: Analyze the Structure of the Products
- **2,2-dimethylpropanal** has the structure:
\[ \text{(CH}_3)_2C(CHO)(CH_3) \]
This indicates that the carbon chain has two methyl groups attached to the second carbon and an aldehyde group.

- **2-butanone** has the structure:
\[ CH_3C(=O)CH_2CH_3 \]
This indicates a ketone with a four-carbon chain.

### Step 3: Determine the Alkene Structure
To find the alkene that produces these two products, we need to consider how the double bond in the alkene can lead to the formation of both products upon ozonolysis.

Let’s assume the alkene is structured as follows:
\[ \text{CH}_3C(CH_3)(CH_3)C=CH(CH_2CH_3) \]
This structure can be represented as 2,2,4-trimethylhex-3-ene.

### Step 4: Verify the Ozonolysis Products
Now, we will perform ozonolysis on this assumed alkene:
1. The double bond between the third and fourth carbon will break.
2. This will yield:
- One fragment leading to 2,2-dimethylpropanal.
- Another fragment leading to 2-butanone.

### Step 5: Confirm the Molecular Formula
Now we check the molecular formula of the alkene:
- Count the number of carbons: 9 (C9)
- Count the number of hydrogens: 18 (H18)

This matches the given molecular formula.

### Conclusion
Thus, the alkene that fits the criteria is **2,2,4-trimethylhex-3-ene**.

### Final Answer
The alkene is **2,2,4-trimethylhex-3-ene** (Option A).

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