Intern:Cyclic compounds in PANGAEA

This is an overview page on cyclic chemical compounds, which can be found in parameter names within PANGAEA. This document redirects to specific guideline pages, based on different classes of cyclic compounds.

=Classes of cyclic compounds= Cyclic compounds can be classified according to different structural characteristics:
 * Ring atoms (only carbons or heteroatoms?)
 * Aromaticity (yes or no?)
 * Number of rings (mono-, bi-, polycycles)
 * Type of ring connection (ring assemblies, ring fusions, bridged rings, spiro-compounds)

Distinct classes use different nomenclature rules to create names describing their structure. The following chapters give a short overview to identify the cyclic compound classes and redirect to more detailed guideline pages.

Ring assemblies
in progress...

Fused ring systems
Especially in German, fused ring systems are also called "condensed/annulated ring system" or "condensed/annulated carbohydrates"

Fused ring systems are defined as polycyclic compounds, which have a maximum number of non-cumulative double bonds (i.e. having as many double bonds as possible, but no atom is connected via two double bonds). The single rings are connected to each other by sharing two atoms (and one bond/edge). This characteristic clearly differentiates them from ring assemblies and spiro compounds.

Fused ring systems can additionally be bridged, partly hydrogenated or cary heteroatoms.

Bridged ring systems
in progress...

Specific natural products
in progress... (e.g. nucleobases, carbohydrates in ring form, cholesteranes, hopanes,...)