In the representation of stereochemical relationships 'anti' means 'on opposite sides' of a reference plane, in contrast to '@S06216@' which means 'on the same side', as in the following examples.
- Two substituents attached to atoms joined by a single bond are anti if the @T06406@ (@D01730@) between the bonds to the substituents is greater than 90°, or @S06216@ if it is less than 90°. (A further distinction is made between @T06406-1@, @T06406-2@, @T06406-3@ and @T06406-4@.)
- In the older literature the terms anti and @S06216@ were used to designate @S05984@ of @O04372@ and related compounds. That usage was superseded by the terms '@C01092@' and 'cis' or E and Z, respectively.
- When the terms are used in the context of @C01033@ or @T06446@, they designate the relative orientation of substituents in the substrate or product:
- Addition to a carbon-carbon double bond: A00381-1.pngA00381-2.png
- Alkene-forming @E02038@: A00381-3.pngA00381-4.pngIn the examples described under (1) and (2) anti processes are always @A00377-1@, and @S06216@ processes are @A00377-2@.
- Addition to a carbon-carbon double bond:
endo, exo, syn, anti