Isomers

Tautomer Generator Plugin

Tautomers are organic compounds that are interconvertible by tautomerization. Tautomerization reaction results in the formal migration of a hydrogen atom or proton, accompanied by a switch of a single bond and adjacent double bond. Commonly, the catalysts of these reactions are acids or bases. In solution a chemical equilibrium of the tautomers will be reached. Some types of tautomers: ketone-enol, amid-imidic acid, lactam-lactim, enamine-imine.

Tautomers of a compound can be determined with the help of the Tautomer Generator Plugin. The plugin does not handle three dimensional molecular coordinates. Two dimensional tautomer representations are generated as outputs from three dimensional molecules. Following options can be adjusted in the Tools > Isomers > Tautomers, Tautomers Options panel:

General options

Advanced options

Note: the number of generated tautomers strongly depends on the options chosen.

For example, the following structures are the calculated tautomers of 4-amino-6-ethoxypyrimidin-2-ol:

Dominant tautomer distribution domtautdistr
Canonical tautomercanonical_tautomer
Generic tautomer and an isotope labelled example generictautomer
Major tautomer majortautomer
All tautomers alltautomers

Stereomer Generator Plugin

The Stereomer Generator Plugin produces all possible stereoisomers of a given compound. The plugin handles both tetrahedral and double bond stereo centers.

Results are displayed in a 2D viewer by default:

To replace your drawn molecule in the sketcher with any of the isomers shown, click on the structure then press "Select" at the bottom of the cells (the result window will be closed).

If "Filter invalid 3D structures" option is switched on in the Stereoisomers Options panel, the stereoisomers can also be displayed in 3D.

References