Meso compound

The meso compound is bisected by an internal plane of symmetry that is not present for the non-meso isomers (indicated by an X).

That is, on reflecting the meso compound through a mirror plane perpendicular to the screen, the same stereochemistry is obtained; this is not the case for the non-meso tartaric acid,[3] which generates the other enantiomer.

The two cis stereoisomers of 1,2-substituted cyclohexanes behave like meso compounds at room temperature in most cases.

[5] At low temperatures, however, this is not the case, as the activation energy for the ring-flip cannot be overcome, and they therefore behave like enantiomers.

Also noteworthy is the fact that when a cyclohexane undergoes a ring flip, the absolute configurations of the stereocenters do not change.