Which of the following is the correct order of priorities in the R,S system?
A) alkyl amino hydroxyl thiol
B) alkyl hydroxyl amino thiol
C) thiol amino hydroxyl alkyl
D) thiol hydroxyl amino alkyl

Question

Which of the following is the correct order of priorities in the R,S system?
A) alkyl > amino > hydroxyl > thiol
B) alkyl > hydroxyl > amino > thiol
C) thiol > amino > hydroxyl > alkyl
D) thiol > hydroxyl > amino > alkyl

Quizplus · Accepted Answer

The R,S system prioritizes functional groups based on their atomic number. In this system, the priorities are determined by looking at the atoms directly attached to the stereocenter. In the given options, thiol has the highest atomic number and thus has the highest priority. Hydroxyl has a higher priority than amino because oxygen has a higher atomic number than nitrogen. Alkyl has the lowest priority because it is only composed of carbon and hydrogen. Therefore, option D (thiol > hydroxyl > amino > alkyl) is the correct order of priorities in the R,S system.

Which of the Following Is the Correct Order of Priorities