Enantiotopic and Diastereotopic Ato

Enantiotopic and Diastereotopic Atoms, Groups, and Faces
Many molecules contain atoms or groups that appear to be equivalent, but with a close inspection will show to be actually different. We can test whether two atoms are equivalent by replacing each of them in turn with some other atom or group. If the new molecules created by this process are identical, the original atoms are equivalent; otherwise they are not. We can distinguish three cases.