Home > Organic Chemistry > Finding R and S for Chiral Centers

What does S configuration mean?

Answer 1

R and S are used to describe the configuration of a chirality center. Chirality center meaning that there are 4 different groups attached to one carbon. To determine whether the chirality center is R or S you have to first prioritize all four groups connected to the chirality center. Then, rotate the molecule so that the fourth priority group is on a dash (pointing away from you). Finally, determine whether the sequence 1-2-3 is (R) clockwise or (S) counterclockwise. Hope this helps.

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Answer 2

Isaac Aronson

S configuration refers to the stereochemistry of a molecule where the highest priority substituent group (determined by the Cahn-Ingold-Prelog priority rules) is positioned on the chiral center pointing away from the observer in a specific spatial arrangement. It is determined based on the sequence of substituents around a chiral center, where the configuration is designated as S (Latin: sinister) if the sequence proceeds in a counterclockwise direction.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.