Morphine on ............. changes to codeine

Options

A. Acetylation
B. Hydroxylation
C. Methylation
D. Oxidation

Answer

### Step-by-Step Solution:

1. **Understanding Morphine and Codeine**:
- Morphine is an alkaloid derived from the opium poppy and is used as a potent analgesic (pain reliever) and tranquilizer.
- Codeine is another alkaloid that is chemically related to morphine and is used for its analgesic and cough suppressant properties.

2. **Identifying the Structural Differences**:
- Both morphine and codeine share a similar core structure, which includes a benzene ring and various other rings.
- The key difference between the two compounds lies in the functional groups attached to their structures.

3. **Chemical Reaction Involved**:
- The transformation of morphine to codeine involves a specific chemical reaction known as **methylation**.
- In this process, a methyl group (–CH3) is added to the hydroxyl group (–OH) present in morphine, converting it to an ether group (–OCH3) in codeine.

4. **Methylation Process**:
- The methylation of morphine to form codeine can be achieved using reagents such as potassium hydroxide (KOH) and iodomethane (CH3I).
- This reaction replaces the hydroxyl group in morphine with a methoxy group in codeine.

5. **Final Answer**:
- Therefore, the correct answer to the question "Morphine on ............. changes to codeine" is **methylation**.