The most stable conformation of 2, 3- dimethyl butane is

Options

A.
B.
C.
D. Nono of these

Answer

To determine the most stable conformation of 2,3-dimethylbutane, we need to analyze the different conformations that this molecule can adopt. Here’s a step-by-step solution:

### Step 1: Understand the Structure of 2,3-Dimethylbutane
2,3-Dimethylbutane is a branched alkane with the following structure:
- It has a butane backbone (4 carbon atoms).
- There are two methyl groups (−CH₃) attached to the second and third carbon atoms of the butane chain.

### Step 2: Identify Possible Conformations
Alkanes can adopt various conformations due to the rotation around the carbon-carbon single bonds. The main types of conformations are:
- Staggered conformation: where the atoms are positioned at maximum distance from each other.
- Eclipsed conformation: where the atoms are positioned directly in front of each other, leading to increased steric hindrance and torsional strain.

### Step 3: Analyze Staggered Conformations
In the staggered conformation, the methyl groups can be positioned in different orientations:
- **Anti conformation**: The two methyl groups are opposite each other (180° apart).
- **Gauche conformation**: The two methyl groups are adjacent (60° apart).

### Step 4: Evaluate Stability
The stability of a conformation is influenced by steric hindrance and torsional strain:
- **Eclipsed conformations** are less stable due to increased steric repulsion between the groups.
- **Staggered conformations** are more stable, with the anti conformation being the most stable due to minimal steric hindrance.

### Step 5: Determine the Most Stable Conformation
For 2,3-dimethylbutane:
- The **anti conformation** is the most stable because the two bulky methyl groups are positioned opposite each other, minimizing repulsion.
- The **gauche conformation** is less stable than the anti conformation due to closer proximity of the methyl groups, which increases steric hindrance.

### Conclusion
The most stable conformation of 2,3-dimethylbutane is the **anti conformation** where the two methyl groups are positioned 180° apart from each other.

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