How do you prioritize the groups on chiral centers?
Aug 11, 2015
The Cahn-Ingold-Prelog sequence rules assign priorities to the groups attached to each chiral centre.
- The atom with higher atomic number receives higher priority.
- If there is a tie, we go one bond further out until we come to the earliest difference.
- If there is still a tie, we keep going further out until we find a difference.
- Double and triple bonds are treated as if they were separate single bonds to the same atom.
Here's an example of how to assign relative priorities.