Which of the following sugars has the configuration (2S 3R, 4R) ?

Options

A.
B.
C.
D.

Answer

To determine which sugar has the configuration (2S, 3R, 4R), we will follow these steps:

### Step 1: Understand the Configuration
The configuration (2S, 3R, 4R) indicates the stereochemistry at the specified carbon atoms in the sugar molecule. The 'S' and 'R' designations refer to the absolute configuration of the chiral centers based on the Cahn-Ingold-Prelog priority rules.

### Step 2: Identify the Sugars
We need to analyze the given options to identify which sugar corresponds to the specified configuration. The options typically consist of different sugar structures.

### Step 3: Assign Priorities
For each sugar structure, we will assign priorities to the substituents attached to the chiral centers (C2, C3, and C4) based on atomic number. The higher the atomic number, the higher the priority.

### Step 4: Determine the Configuration
Using the assigned priorities, we will determine the configuration at each chiral center:
- For C2, if the order of substituents is anticlockwise with the lowest priority group pointing away, it is 'S'; if clockwise, it is 'R'.
- For C3 and C4, we will do the same.

### Step 5: Check Each Option
We will systematically check each sugar option:
1. Draw the structure of the sugar.
2. Assign priorities to the substituents at C2, C3, and C4.
3. Determine the configuration for each carbon based on the priority order.

### Step 6: Compare with the Given Configuration
After determining the configurations for each sugar, we will compare them with the required (2S, 3R, 4R) configuration to find the correct answer.

### Conclusion
After analyzing all the options, we will identify which sugar has the configuration (2S, 3R, 4R).

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