Title: cis-fused
Long Title: IUPAC Gold Book - <i>cis</i>-fused
DOI: 10.1351/goldbook.C01089
Status: current

Definition
Steric relations at saturated bridgeheads common to two rings are denoted by cis or trans, followed by a hyphen and placed before the name of the ring system, according to the relative positions of the exocyclic atoms or groups attached to the bridgeheads. Such rings are said to be cis-fused or trans-fused.

Related Terms
- <em>trans</em>: https://goldbook.iupac.org/terms/view/C01092
- bridgeheads: https://goldbook.iupac.org/terms/view/B00736

Source
- Blue Book, p. 479 (https://www.acdlabs.com/iupac/nomenclature/)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/C01089/html
- json: https://goldbook.iupac.org/terms/view/C01089/json
- xml: https://goldbook.iupac.org/terms/view/C01089/xml

Citation: Citation: '<i>cis</i>-fused' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.C01089
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Accessed: 2026-05-15T02:29:56+00:00