Okay, now we have our second exercise.

The second question was, explain what a Stereocenter and a Kialitih Center is and what is an Anticelectivity.

Okay, first we should start with the term estereoisomers.

What is that?

These are isomers, these isomers are molecules that form exactly the same constitution.

For example, here there is an aromatic ring with two methyl substitutes,

but the arrangement of the groups in three-dimensional space is different.

What are the entomers?

They are just estereotomers that behave like a mirror image of another and cannot be used for cover.

That means they don't have to be superimposable. I don't know how to say that in German.

For example, here as an analogy, the hands up here are an example of enantiomers.

And what is an estereocentrum?

An estereocentrum is this atom here in the molecule that is connected with different ligands, so that the exchange of two substitutes leads to an estereotomer.

Most of the time it is a carbon atom with four different ligands, for example, with which the ligands have different nort and

when an entomers of the molecule is formed, then one speaks of an estereocentrum.

Therefore, it is important to understand that each estereocentrum is an estereocentrum,

but not every estereocentrum is an estereocentrum.

It is important to understand and distinguish.

And finally, what is enantio-selectivity?

It is the ratio of the reaction velocities of two enantiomers in their conversion.

That means, what does that mean? If in a chemical reaction, my duct or product, for example,

breaks up two possible enantiomers and the reaction has a high enantio-selectivity,

that means that one enantium is converted much faster than the other.