How many optically active stereomers are possible for butane - 2,3- diol ?

Options

A. 3
B. 4
C. 1
D. 2

Answer

A

Explanation

No. of asymmetric or chiral carbon = 2
Therefore no. of optical isomers `=2^(n)=2^(n)=4`
No . Of optically active steremers `=4-1=3`, because seso compound is optically inactive due to internal compensation.