Optical isomerism Flashcards
1
Q
When does optical isomerism occur?
A
When there is a chiral carbon - which has 4 different groups attached to it
2
Q
Why is a chiral carbon needed?
A
To ensure there is no symmetry in the molecule
3
Q
What are enantiomers?
A
A pair of optical isomers.
4
Q
What is a racemic mixture?
A
A mixture containing equal amounts of each enantiomer. As a result, each enantiomer rotates plane polarised light equally in opposite directions, so the overall effect is cancelled out. So the mixture is optically inactive
5
Q
How is a racemic mixture formed through nucleophilic addition?
A
The nucleophile needs to be able to attack the molecule with a carbonyl group from above or below the C=O bond, so forming equal amounts of each enantiomer.
