Question

The number of optical isomers of $C{H}_{3}CH\left(OH\right)CHO$ is:

• A. $0$
• B. $2$
• C. $3$
• D. $4$

Answer 1

The correct option is D $4$

Knowing the number of asymmetric carbon atoms, one can calculate the maximum possible number of stereoisomers for any given molecule as follows: If n is the number of asymmetric carbon atoms then the maximum number of isomers $=2^n$

A compound with 2 asymmetric carbon atoms has $2^2=4$ stereoisomers