Which of the following substituents has the highest priority according to the Cahn-Ingold-Prelog system?

Question

Quizplus · Accepted Answer

According to the Cahn-Ingold-Prelog system, the priority of substituents is determined by the atomic number of the atoms directly bonded to the parent carbon. In this case, -COOH has the highest priority as it contains an oxygen atom (atomic number 8) directly bonded to the parent carbon, whereas -CHO only has a carbon atom (atomic number 6) directly bonded to the parent carbon. The other two substituents contain sulfur (atomic number 16), which has a lower atomic number than oxygen.

Which of the Following Substituents Has the Highest Priority According