Questions: What is the stereochemistry of isoleucine? C 2 is (S) and C 3 is (S) C 2 is (R) and C 3 is (R) C 2 is (R) and C 3 is (S) C2 is (S) and C3 is (R)

Solution Steps

Isoleucine has two chiral centers located at carbon 2 (C2) and carbon 3 (C3).

To determine the configuration of C2, we need to assign priorities to the substituents attached to C2 based on the Cahn-Ingold-Prelog priority rules. The substituents are:

1. -NH\(_2\) (highest priority)
2. -COOH
3. -CH(CH\(_3\))-CH\(_2\)-CH\(_3\)
4. -H (lowest priority)

When viewed with the lowest priority group (-H) in the back, the sequence of priorities (1 to 3) follows a counterclockwise direction, indicating an \(S\) configuration.

Similarly, for C3, the substituents are:

1. -CH\(_2\)-CH\(_3\) (highest priority)
2. -CH\(_3\)
3. -CH(NH\(_2\))-COOH
4. -H (lowest priority)

When viewed with the lowest priority group (-H) in the back, the sequence of priorities (1 to 3) follows a clockwise direction, indicating an \(R\) configuration.

Final Answer