Question

What are stereoisomers? Give an example.

Answer 1

Stereoisomers

• Stereoisomers have the same molecular formula and chemical bonds but they have different spatial arrangements.
• Stereoisomers can be subdivided into two parts that are configurational and conformational isomers.

Configurational isomerism

• This type of isomerism is non-superimposable and non-interconvertible by rotation around single bonds.
• They can be interconverted by breaking and making bonds.
• These are of two types that are Enantiomers(optical isomers), and diastereomers.

1. Enantiomers

• In this, two isomers are mirror images of each other.
• It is also known as inversional isomerism.
• For example, the enantiomers of lactic acid is given below:

2. Diastereomers

• These do not mirror images of each other.
• These are also known as geometrical isomers.
• For example, diastereomers of But-2-ene is shown below:

Conformational isomers

• These are non-superimposable but easily interconvertible by rotation about single bonds.
• Cycloalkane and alkanes show this type of isomerism.
• For example, the conformational isomers of ethane is shown below: