Ranking Groups

The Cahn–Ingold–Prelog rules

An interactive lesson with 5 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Rank by atomic number of the attached atom; break ties one bond further out.
• Double bonds count their atom twice; first difference wins.

Steps

1. Who comes first?
2. Rank by atomic number
3. Common groups
4. Alanine
5. A closer call