Which of the following pairs are diastereomers?

Options

A. `{:(" "CHO" "CHO),(" | |"),(H-C-OH and HO-C-H""),(" | |"),(" "CH_(3)" "CH_(3)):}`
B.
C.
D. All of these

Answer

To determine which pairs are diastereomers, we need to understand the definition of diastereomers. Diastereomers are stereoisomers that are not related as mirror images. They must have at least one chiral center and differ in configuration at one or more of those centers, but not all.

Let's analyze the given pairs step by step:

### Step 1: Identify Chiral Centers
For each pair of compounds, identify the chiral centers. A chiral center is typically a carbon atom that is bonded to four different groups.

**Hint:** Look for carbon atoms that have four distinct substituents.

### Step 2: Check for Mirror Images
Determine if the two compounds in each pair are mirror images of each other. If they are mirror images, they are enantiomers, not diastereomers.

**Hint:** Draw the mirror image of one compound and see if it can be superimposed on the other.

### Step 3: Compare Configurations
For pairs that have chiral centers, compare the configurations (R/S) of the chiral centers. If they differ at one or more centers but not all, they are diastereomers.

**Hint:** Use the Cahn-Ingold-Prelog priority rules to assign R/S configurations to the chiral centers.

### Step 4: Identify Diastereomers
After analyzing each pair, identify which pairs are diastereomers based on the previous steps.

**Hint:** Look for pairs that have at least one chiral center with different configurations but are not mirror images.

### Conclusion
Based on the analysis, we conclude that option C contains the pair of compounds that are diastereomers, as they do not form mirror images of each other.

**Final Answer:** The correct option is C.