What is achiral in organic chemistry?

1 Answer
Sep 30, 2016

A molecule that can be superimposed on its mirror image.

Explanation:

Can you superimpose your right hand on the left hand of your identical twin? You cannot because hands are chiral or handed (the word #"chiral"# comes from #chiepsiloniotarho#, the Greek word for #"hand"#). If a molecule is achiral it is superposable on its mirror image.

In general an achiral carbon centre has at least two of the same groups attached to the carbon, i.e. #R_2CR'R''#. A carbon with 4 different substituents, #CR_1R_2R_3R_4#, will necessarily generate 2 optical isomers.