Which of the following is the correct order of priorities in the R,S system?
A) tert-butyl butyl isopropyl propyl
B) tert-butyl isopropyl butyl propyl
C) isopropyl tert-butyl propyl butyl
D) propyl butyl isopropyl tert-butyl

Question

Which of the following is the correct order of priorities in the R,S system?
A) tert-butyl > butyl > isopropyl > propyl
B) tert-butyl > isopropyl > butyl > propyl
C) isopropyl > tert-butyl > propyl > butyl
D) propyl > butyl >isopropyl > tert-butyl

Quizplus · Accepted Answer

The R,S system prioritizes substituents based on their atomic number. In this order, tert-butyl (three carbons) has the highest atomic number, followed by isopropyl (two carbons and one methyl group), butyl (four carbons), and propyl (three carbons). Therefore, tert-butyl has the highest priority, followed by isopropyl, then butyl, and finally propyl. Choice B correctly lists the groups in order of decreasing priority.

Which of the Following Is the Correct Order of Priorities