Which among the following compound has [L] configuration

Options

A. `H-underset(CH_2OH)underset(|)overset(CHO)overset(|)C-OH`
B. `H-underset(CH_2OH)underset(|)overset(COOH)overset(|)C-NH_2`
C. `{:(" "COOH),(" |"),(" "H-C-OH),(" |"),(" "H-C-OH),(" |"),(" "HO-C-H),(" |"),(" "CH_(2)OH):}`
D. `{:(" "CHO),(" |"),(" "HO-C-H),(" |"),(" "H-C-OH),(" |"),(" "CH_(2)OH):}`

Answer

To determine which compound has an L-configuration, we will follow these steps:

### Step 1: Identify the Oxidized and Reduced Groups
In the context of amino acids or carbohydrates, the oxidized group (aldehyde or carboxylic acid) is typically at the top of the structure, while the reduced group (alcohol) is at the bottom.

**Hint:** Look for the functional groups at the top and bottom of the molecule.

### Step 2: Locate the Second Last Carbon
Next, we need to focus on the second last carbon in the chain. This carbon is crucial for determining the configuration (L or D).

**Hint:** The second last carbon is the one directly above the reduced group.

### Step 3: Determine the Position of the Hydroxyl or Amine Group
Now, check the position of the hydroxyl (-OH) or amine (-NH2) group attached to the second last carbon.

- If the hydroxyl or amine group is on the left side, the configuration is L.
- If it is on the right side, the configuration is D.

**Hint:** Visualize the molecule like a mirror image; left corresponds to L and right corresponds to D.

### Step 4: Analyze Each Compound
Go through each of the given compounds and apply the above steps:

1. **Compound A:** Hydroxyl group on the right → D configuration.
2. **Compound B:** Amine group on the right → D configuration.
3. **Compound C:** Hydroxyl group on the left (second last carbon) → L configuration.
4. **Compound D:** Hydroxyl group on the right → D configuration.

**Hint:** Pay close attention to the positioning of the functional groups as you analyze each compound.

### Step 5: Conclusion
After analyzing all the compounds, we find that **Compound C** has the L-configuration because the hydroxyl group is positioned on the left side of the second last carbon.

**Final Answer:** The compound with L-configuration is **Compound C**.

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