In the reaction with aq. Sodium hydroxide which of the following compounds was undergo inversion and `S_N2` mechanism?

Options

A.
B.
C. `(C_2H_6)_2CHCI`
D. `(CH_3)_3 CCI`

Answer

To determine which compound undergoes inversion and follows an \( S_N2 \) mechanism when reacting with aqueous sodium hydroxide (\( NaOH \)), we need to analyze the characteristics of the \( S_N2 \) reaction mechanism.

### Step-by-Step Solution:

1. **Understanding the \( S_N2 \) Mechanism:**
- The \( S_N2 \) mechanism involves a nucleophile attacking the electrophile in a single concerted step, leading to the inversion of configuration at the carbon atom. This is because the nucleophile attacks from the opposite side of the leaving group.

2. **Identifying the Degree of Carbon:**
- The reactivity in \( S_N2 \) reactions is influenced by the degree of substitution of the carbon atom attached to the leaving group (in this case, a halide).
- \( S_N2 \) reactions are fastest with primary (1°) alkyl halides, followed by secondary (2°) alkyl halides, and are very slow or non-existent with tertiary (3°) alkyl halides due to steric hindrance.

3. **Analyzing the Given Compounds:**
- We need to look at the options provided and identify the degree of the carbon atom bonded to the leaving group (e.g., Cl).
- If the compound is a primary alkyl halide, it is likely to undergo \( S_N2 \) with inversion.
- If it is a secondary alkyl halide, it may also undergo \( S_N2 \) but with less efficiency compared to primary.
- Tertiary alkyl halides will not undergo \( S_N2 \) due to steric hindrance.

4. **Selecting the Correct Compound:**
- Upon reviewing the options, we identify the compound that has a primary carbon attached to the leaving group.
- This compound will be the one that undergoes inversion and follows the \( S_N2 \) mechanism effectively.

5. **Conclusion:**
- The correct answer is the compound that has a primary carbon atom attached to the halide, as it will undergo \( S_N2 \) mechanism with inversion when reacted with aqueous sodium hydroxide.

### Final Answer:
The compound that undergoes inversion and follows the \( S_N2 \) mechanism is the one with a primary carbon atom attached to the leaving group.

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