Question

D(-)-Erythrose$\stackrel{NaB{H}_4}{\to }P$
D(-)-Threose $\stackrel{NaB{H}_4}{\to }R$
Which of the following statement is correct about $P$ and $R$?

• A. Both are optically active
• B. Both are optically inactive
• C. $P$ is optically inactive and $R$ is optically active
• D. Neither $P$ nor $R$ has asymmetric carbon

Answer 1

The correct option is C $P$ is optically inactive and $R$ is optically active

$P$ is optically inactive as it contains the center of symmetry and $R$ is optically active as it contains no element of symmetry.