Question

Find total number of stereoisomers for each compound given below:

A.5
B.6
C.4
D.None

Answer 1

Hint: The number of stereoisomers will depend on chiral carbon. The chiral carbons are those carbons which have all the different groups attached to it.

Complete step by step solution:

In the above molecule there are two chiral atoms. One on which hydroxyl group is attached and the other on which methyl group is attached. They have 4 different groups around them.
 One chiral carbon corresponds to two stereoisomers that are R and S, so two carbon atoms will give us 4 stereoisomers.

Thus, the correct option is 4 that is C.

Additional information:
Isomers are those molecules which have the same molecular formula but have different physical and chemical properties.Stereoisomer is those isomers in which the molecules differ in the arrangement of atoms in space. Structural isomers are those having the same molecular formula but different properties due to different structures. They are classified as chain isomerism, position isomerism, functional group isomerism and linking isomerism. Functional group isomerism is that structural isomerism which has the same molecular formula but different functional group chain isomerism by that structural isomerism which has the same molecular formula but different length of principal carbon. Chain position isomerism is that structural isomerism which has the same molecular formula but different position of functional groups or multiple bond or side substituents. Ring chain isomerism is that structural isomerism which has the same molecular formula but has either the multiple bonds or ring with respect to its isomer.

Note:
Amines do not show optical activity due to their continuous inversion which is known as Walden inversion. The stereochemistry of amine changes from R to S continuously, hence in spite of having different groups they do not show optical activity.