Question

What are Mesomers?? Can we apply CIP nomenclature to Mesomers to make R nd S configurations???

Answer 1

Here's what I get.

Explanation:

Mesomer is just another term for a meso compound·

A meso compound is a type of stereoisomer that has two or more chiral centres but is optically inactive because it has an internal plane of symmetry.

cis-1,2-Dichlorocyclohexane is a meso compound.

The two mirror images are superimposable on each other and each molecule is divided into two mirror-image halves by the horizontal red lines.

We can use the Cahn-Ingold-Prelog system to name these structures.

The left-hand structure would be named (`1R,2S`)-1,2 dichlorocyclohexane, while the other would be named (`1S,2R`)-1,2 dichlorocyclohexane.

However, they are the same compound, so there is only correct IUPAC name. It is based on the arbitrary assumption that the prefix first cited is `R`.

Thus, both structures are named (`1R,2S`)-1,2 dichlorocyclohexane.