antarafacial

Antarafacial and suprafacial are two topological concepts in organic chemistry describing the relationship between two simultaneous chemical bond making and/or bond breaking processes in or around a reaction center. The reaction center can be a p-orbital, a conjugated system or even a sigma bond.

• This relationship is antarafacial when opposite faces are involved (think anti).
• It is suprafacial when both changes occur at the same face.