Stereochemistry: Chirality and Enantiomers
Start with the big picture
A molecule is chiral when it cannot be superimposed on its mirror image; an internal plane of symmetry rules out chirality. A tetrahedral atom with four different substituents is a common stereogenic center, but chirality can also arise from other structural features. Enantiomers are mirror-image stereoisomers, and their configurations can be assigned using Cahn–Ingold–Prelog priority rules. The lesson distinguishes configuration labels from the empirical signs of optical rotation and introduces racemic mixtures and enantiomeric excess as ways to describe composition. It also previews diastereomers, symmetry-related exceptions, and approaches to separating or preparing enantiomers—concepts relevant to pharmaceutical development and quality control.
What you'll learn
- Define molecular chirality and identify the role of symmetry.
- Describe stereogenic centers and distinguish enantiomers from diastereomers.
- Outline how CIP priorities determine R and S configurations.
- Explain racemic mixtures and the purpose of enantiomeric excess.
- Recognize methods used to separate or prepare enantiomers.
Continue your study
Work through the complete notes and reinforce the topic with the study tools available in the full lesson.
