Cahn-Ingold-Prelog Convention (Determining R/S)

The video tutorial explains how to differentiate between enantiomers by assigning absolute configuration to chiral centers using the Cahn-Ingold-Prelog convention. It covers identifying chiral centers, assigning priority based on atomic mass, and determining absolute configuration. The tutorial also provides examples and tricks for cases where the lowest priority group is not positioned away from the viewer.

What is the purpose of the Cahn-Ingold-Prelog convention?

• To calculate the density of molecules

• To determine the boiling point of substances

• To identify the molecular weight of compounds

• To differentiate between enantiomers

How do you identify a chiral center in a molecule?

• By finding a carbon atom bonded to four different groups

• By locating the heaviest atom in the molecule

• By finding a carbon atom bonded to identical groups

• By identifying the longest carbon chain

What determines the priority of groups attached to a chiral center?

• The overall molecular weight

• The length of the carbon chain

• The atomic mass of the atoms directly attached

• The number of hydrogen atoms present

What configuration is assigned if the circle from group 1 to 2 to 3 is clockwise?

• S configuration

• R configuration

• Z configuration

• E configuration

What should you do if the lowest priority group is not away from you?

• Always assign S configuration

• Ignore the configuration

• Always assign R configuration

• Mentally reposition yourself or swap groups

What happens to the stereochemistry if you swap two groups on a chiral center?

• It remains unchanged

• It becomes undefined

• It doubles

• It inverts

In the example where the lowest priority group is in the plane of the board, what is a suggested method to assign configuration?

• Assign configuration based on intuition

• Mentally orient yourself to view the group as away

• Swap the lowest priority group with another

• Use a molecular model

What is the result of swapping the hydrogen and fluorine in the example provided?

• The configuration remains the same

• The configuration becomes R

• The configuration becomes undefined

• The configuration becomes S

Why is it important to invert the answer after swapping groups on a chiral center?

• To increase the molecular weight

• To ensure the configuration is correct

• To simplify the molecular structure

• To decrease the molecular weight

What is a key skill needed for mentally orienting molecules to assign configuration?

• Mathematical calculation

• Spatial reasoning

• Biological analysis

• Chemical synthesis