We’re being asked to identify the meso compound among the given structures.
Recall that meso compounds are superimposable mirror images despite having chiral centers. Meso compounds:
• have an internal line of symmetry → achiral
• follow the 2n – 1 rule for total stereoisomers → two stereoisomers are identical
A compound will be meso if it follows these criteria:
1. It has 2 or more chiral centers.
2. It is atomically symmetrical → symmetrical in connectivity
3. An even number of chiral centers have opposite configuration (if one is R, the other should be S)