Question

Which of the following is optically active?

• A. $CH_3 - \underset{\overset{|}{O}H}{\overset{\underset{|}{H}}{C}} -\underset{\overset{|}{O}H}{\overset{\underset{|}{H}}{C}}-CH_3$
• B. $ C{{H}_{3}}-CHOH-C{{H}_{3}} $
• C. $CH_3 - \underset{\overset{||}{O}}{C}- \underset{\overset{|}{B}r}{\overset{\underset{|}{B}r}{C}}-COOH$
• D. $CH_3 - CH_2 - \underset{\overset{|}{O}H}{C} = O$

Answer 1

Answer: (A)

Optically active compounds have at least one asymmetric or chiral carbon atom. Compound given in option [a] contains two chiral carbon atoms as
$ CH_3 - \underset{\overset{|}{O}H}{\overset{\underset{*|}{H}}{C}}- \underset{\overset{|}{O}H}{\overset{\underset{*|}{H}}{C}}-CH_3 $
$ \therefore $ it is optically active.