Question

Consider the chirality center in the compound below. 

a.What is the highest priority substituent group? 

b.What is the second highest priority substituent group?

Answer 1

\(\mathrm{R}\) and \(\mathrm{S}\) configuration can be assigned to the compound by using the following CIP (CahnIngold-Prelog) sequence rules:

Chirality center: An atom (usual carbon) bonded to four different atoms or groups is known as the chiral center.

Rule 1: Select the chiral center in the compound and assign priorities to the atoms based on their atomic number. The atom with the highest atomic number gets the priority, and the atom has the least atomic number (usual hydrogen) fourth priority.

Rule 2: If the isotopes of the same atom are attached to the chiral center, then the higher atomic mass receives higher priority.

Rule 3: If the first atom of each substituent is the same, give priority to the second atom in each substituent. This process continues to the third and fourth until the rule difference is reached.

Rule 4: If the substituents have multiple bonds, the multiple bonded atoms are considered the same number of single-bonded atoms.