Chirality/Stereochemistry Flashcards
What is an enantiomer?
A type of stereoisomers which is a non-superimposable,
mirror image.
e.g. your hands or your shoes
What characterises an enantiomer?
• A chiral/stereogenic centre
What is a chiral/stereogenic centre?
A chiral centre is a place in a molecule where a carbon is bonded to four different groups.
They are sometimes indicated by dashes or wedges in the structural formula but not always!
What does an R and S configuration mean?
An R or S configuration is a way of describing a stereogenic carbon.
They are ranked by priority of atomic number (highest first).
What is an R configuration?
The priority ranking of the groups coming off of a stereogenic carbon going in a clockwise direction.
What is an S configuration?
The priority ranking of the groups coming off of the stereogenic carbon going in an anti-clockwise direction.
How should a molecule be rotated to determine an R or S configuration?
The lowest priority group (the lowest atomic number) is pointing backwards. (to the back of the page - a dash)
DO NOT JUST SWAP GROUPS
What is a diastereomer?
A non-superimposable, non-mirrorimage molecule with multiple stereogenic centres.
