https://doi.org/10.1351/goldbook.A00381
In the representation of stereochemical relationships 'anti' means 'on opposite sides' of a reference plane, in contrast to '@[email protected]' 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 @[email protected] (@[email protected]) between the bonds to the substituents is greater than 90°, or @[email protected] if it is less than 90°. (A further distinction is made between @[email protected], @[email protected], @[email protected] and @[email protected])
- In the older literature the terms anti and @[email protected] were used to designate @[email protected] of @[email protected] and related compounds. That usage was superseded by the terms '@[email protected]' and 'cis' or E and Z, respectively.
- When the terms are used in the context of @[email protected] or @[email protected], 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 @[email protected]: A00381-3.pngA00381-4.pngIn the examples described under (1) and (2) anti processes are always @[email protected], and @[email protected] processes are @[email protected]
- Addition to a carbon-carbon double bond:
See also:
endo, exo, syn, anti