4cis2

4cis2 is a shorthand that appears in some chemical literature to indicate a cis stereochemical relationship between substituents at positions 2 and 4 on a ring or polycyclic framework. Because it is not a formal IUPAC name, its exact meaning depends on the scaffold and the source, and it may be interpreted differently in different contexts.

In simple monocyclic rings such as cyclohexane derivatives, 4cis2 could describe a cis arrangement of substituents at the C-2 and C-4 positions, meaning both substituents lie on the same face of the ring. In fused or more complex ring systems, the numbers 2 and 4 may refer to specific ring positions across the fusion, and “cis” would denote a relative orientation rather than an absolute configuration.

Because 4cis2 is not standardized, chemists generally avoid such shorthand in formal naming. More explicit conventions are used, including full locant-based descriptions (for example, a 2,4-disubstituted system with specified cis orientation), stereochemical descriptors at each stereocenter (R/S), or modern representations like SMILES or InChI that encode the exact structure.

If you encounter 4cis2 in a text, it is advisable to consult the source’s notation conventions or the experimental details to determine precisely what is meant for that particular scaffold. See also stereochemistry, cis-trans isomerism, E/Z notation, IUPAC nomenclature, and SMILES for broader context.