The possible stereo-structures of CH3CHOHCOOH, which are optically active, are called
- atropisomers
- enantiomers
- mesomers
- diastereomers
Answer
(2) enantiomers
Solution
CH3- *CH(OH)-COOH (lactic acid) has one chiral carbon (four different groups: H, CH3, OH, COOH).
⇒ It exists as two optically active forms, (+) and (–), which are non-superimposable mirror images of each other.
As per NCERT, stereoisomers related as non-superimposable mirror images are called enantiomers.
Answer: (2)