Name two methods which are commonly used to convert `gtC=O` grou into a `gtCH_(2)` group.

Explanation

To convert a carbonyl group (C=O) into a methylene group (CH2), we can use the following two methods:

### Step-by-Step Solution:

1. **Wolf-Kishner Reduction**:
- The Wolf-Kishner reduction is a method that involves the hydrazone formation followed by the reduction of the carbonyl compound.
- First, the carbonyl compound (aldehyde or ketone) is treated with hydrazine (NH2NH2) to form a hydrazone.
- The hydrazone is then heated with a strong base (usually potassium hydroxide, KOH) and a high-boiling solvent (like ethylene glycol) to eliminate nitrogen gas (N2) and reduce the carbonyl group to a methylene group (CH2).
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