Is cis -1,2-dibromocyclohexane a meso compound?

1 Answer
Oct 2, 2015

Yes, cis-1,2-dibromocyclohexane is a meso compound.


The cyclohexane molecule exists as two conformers, the chair form (most stable) and the boat form (least stable).

The chair form doesn't have a plane of symmetry thus it isn't a meso compound, it is a chiral molecule.

However the boat form does have a plane of symmetry, even with the bromine attached on the same side (cis). Thus the molecule is a meso compound, meso means that there is symmetry in a compound with assymetric carbons (chirality centers)., which makes it achiral.

Image showing the two conformers and the whether there is symmetry or not:
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Image from:

Therefore the molecule cis-1,2-dibromocyclohexane is a meso compound because it meets the criteria of one conformer being a meso in this case.

Hope I helped :)