`CH_(3)-CH=CH-CH=CH-overset(O)overset(||)(C)-H overset("dil. "OH^(-))to (A)`. (A) is

Options

A. `CH_(3)-(CH=CH)_(4)-C-H`
B.
C.
D.

Answer

To solve the given question, we need to analyze the reaction of the compound with dilute OH⁻. The compound provided is a diene with a terminal hydrogen atom, and we will follow the steps to determine the product (A).

### Step-by-Step Solution:

1. **Identify the Compound**: The compound is CH₃-CH=CH-CH=CH-CHO, which is a diene with an aldehyde functional group at one end.

2. **Reaction with Dilute OH⁻**: When the compound reacts with dilute OH⁻, the hydroxide ion will act as a base and abstract a proton (H⁺) from the terminal hydrogen of the aldehyde group.

3. **Formation of the Intermediate**: After the abstraction of the terminal hydrogen, we will have a negatively charged intermediate. The structure will now have a negative charge on the carbon that was previously bonded to the hydrogen.

4. **Resonance Stabilization**: The negative charge can be stabilized through resonance. The negative charge can delocalize onto the adjacent double bond, leading to a more stable structure.

5. **Nucleophilic Attack**: The negatively charged intermediate can now act as a nucleophile. It will attack the electrophilic carbon of the adjacent double bond, leading to the formation of a new bond.

6. **Final Product (A)**: After the nucleophilic attack and subsequent rearrangement, the final product will be a conjugated system with an OH group. The product can be represented as CH₂=CH-CH=CH-CHOH (an allylic alcohol).

### Final Structure:
The product (A) is CH₂=CH-CH=CH-CHOH.