View source for Nomenclature of polycyclic compounds

The '''nomenclature of polycyclic compounds''' is a specialised area of [[Nomenclature of organic chemistry|organic nomenclature]]. There are several methods, depending on the particular compound:
*[[von Baeyer nomenclature]],<ref name="von Baeyer">{{IUPAC von Baeyer 1999}}.</ref> including
**[[spiro nomenclature]]<ref name="spiro">{{IUPAC spiro 1999}}.</ref>
*[[fusion nomenclature]]<ref name="fusion">{{IUPAC fused rings 1998}}.</ref>
*[[Nomenclature of natural products|natural product nomenclature]],<ref>{{IUPAC natural products 1999}}.</ref> which can be further subdivided into
**[[Nomenclature of steroids|steroid nomenclature]]<ref>{{IUPAC-IUB steroids 1989}}.</ref>
**[[Nomenclature of terpenes|terpene nomenclature]]
**[[Nomenclature of alkaloids|alkaloid nomenclature]]
*[[Nomenclature of heterocyclic compounds|heterocyclic nomenclature]] contains several [[retained name]]s for bi- and tri-cyclic compounds
While there may be choice of nomenclature methods for a given compound, it is normal to use natural product nomenclature for [[steroid]]s, [[terpene]]s, [[alkaloid]]s and other compounds of biological origin; fusion nomenclature for fused ring systems such as [[polycyclic aromatic hydrocarbon]]s; and von Baeyer nomenclature for other polycyclic compounds. The systems are not completely independent of one another.

==Definitions==
;Polycyclic compound
A compound which, for nomenclature purposes, requires at least two scissions to convert it into an open-chain compound.<ref name="von Baeyer"/>

;Spiro compound
A compound which has two (or three) rings which have only one atom in common and the two (or three) rings are not linked by a bridge. The common atom is known as a [[spiro atom]].<ref name="spiro"/>

;Fusion
The process of joining rings, for nomenclature purposes, so that two rings have two atoms and one bond in common, the resulting compound being regarded as being derived from the two rings as separate entities.<ref name="fusion"/>

==References==
{{reflist}}

[[Category:Chemical nomenclature|Polycyclic compounds]]

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