Which of the following structures has the S configuration?

Question

Quizplus · Accepted Answer

Only structures I and II have stereocenters and are chiral. Assigning priorities to the substituents and following the Cahn-Ingold-Prelog priority rules, we can determine that:

Structure I has the highest priority group (COOH) on the left side, H on the back, CH3 on the right, and NH2 on the front. Therefore, it has an S configuration.

Structure II has the highest priority group (COOH) on the left side, H on the front, CH3 on the back, and OH on the right. Therefore, it also has an S configuration.

Structure III does not have a stereocenter, so it does not have a configuration to assign.

Which of the Following Structures Has the S Configuration