Name two methods commonly used to convert a carbonyl `(gtC=O)` group into a methylene `(gtCH_(2))` group.

Explanation

To convert a carbonyl group (C=O) into a methylene group (CH₂), two commonly used methods are:

### Method 1: Wolff-Kishner Reduction
1. **Reagents Used**: The Wolff-Kishner reduction employs hydrazine (NH₂NH₂) as the reducing agent.
2. **Basic Medium**: The reaction is carried out in a basic medium, typically using potassium hydroxide (KOH).
3. **Reaction Mechanism**:
- The carbonyl compound reacts with hydrazine to form a hydrazone.
- Upon heating in the presence of a strong base, the hydrazone undergoes dehydrazination, resulting in the conversion of the carbonyl group into a methylene group (CH₂).
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