Question

The following compounds may exist as two or more stereoisomers. These may be classified as enantiomer pairs or meso compounds.
How many meso compounds exist for each of the above structures?

Answer 1

If a molecule has to be a meso compound, it has to satisfy the following rules:

1. The molecule must have at least two stereocenters.

2. The molecule must have an internal mirror plane that bisects the molecule.

3. Both halves of the mirror plane should be mirror images to each other.

compounds (a), (b), (e) are meso compounds.