Question

What does R and S mean in stereochemistry?

Answer 1

Hint: We have to know that an absolute configuration indicates the arrangement of atoms in space of chiral molecular groups and its stereochemical explanation. We could obtain the absolute configuration through X-ray crystallography. In stereochemistry, the descriptors R (or) S are given by priority rules designed by Cahn-Ingold-Prelog.

Complete answer:
Cahn, Ingold, and Prelog fostered a framework that, paying little mind to the course we are taking direction at the particle, will consistently give a similar name (not at all like the wedge and dash representation).
Furthermore, that is the reason this is otherwise called the Absolute Configuration or most ordinarily alluded to as the R and S notation.
To appoint the absolute configuration, we need to initially find the carbon(s) with four unique groups (iotas) associated with it. These are called chirality centers.
Give every atom associated with the chiral center a need dependent on its atomic number. When the atomic number is higher, the priority would be higher.
An arrow is drawn from starting with priority one, then to priority two and so on,
On the off chance that the arrowpasses through clockwise, as for this situation, the outright configuration is R.
Instead of this, assuming the arrow passes through counterclockwise, the outright configuration is S.
In stereochemistry, R refers to Rectus and S refers to Sinister.

Note:
In simple words, we can say that the R/S system is a nomenclature which is used for representing enantiomers. We have to remember that if priority of substituent groups reduces in clockwise direction, then we have to label it as R and if it reduces in counterclockwise direction, then we have to label it as S.