What is retention and inversion of configuration ? Explain with suitable example.

Explanation

If in a chemical reaction, no bonds to the stereocentre (chiral centre) are broken, the product will have the same general configuration of the groups around the stereocentre as that of reactant. Such a reaction is said to proceed with the retention of configuration. Thus, the preservation of the spatial arrangment of bonds to an asymmetric centre during a chemical reaction is called retention of configuration. Consider an example of the reaction that takes place when (-) -2-methylbutan-1-ol is heated with hydrochloric acid (conc.)
However, if in a product, the atom occupies the opposite position to the replaced ligand at a chiral center, it is known as inversion of configuration.

The configuration at asymmetric center in the reactant and product is same but the sign of the optical rotation has changed in the product. This is because the two different compounds with same configuration at asymmetric center may have different optical rotation. One may be dextrorotatory while other may be laevorotatory.