Software that can predict organic reaction products is a hotly pursued but unsolved challenge because of its obvious potential in pharmaceutical industry. However,  stereochemistry is not included in the vast majority of the previous efforts, although its control is often the most challenging and interesting part of organic reactions. This is not an accidental omission but maybe an inherent problem of molecule representations in computer. The molecule representation methods (strings, tables, matrix etc.) used by programmers differ from those of chemists, which may be the reason that the software can not fully take advantage of the knowledges and wisdoms of chemists.  

VirtualChemist is an organic reaction software suite focusing on stereochemistry. A new design ( ) was proposed to translate molecule Lewis structure to machine readable format data. Using Lewis formula as the only user input, which can be either an existing molecule or a molecule unknown yet,
(1). Stereoisomer can identify all the stereocenters and configurational isomers for the compounds with tetrahedral carbon stereocenters.  It can also handle molecules with carbon-carbon and carbon-nitrogen double bond stereocenters. With sigma-bond rotation and "Flip" functionality, it can present conformational isomers.
(2). Tautomer can simulate the practice of chemists writing acid/base catalyzed tautomerization and enumerate all the tautomers.
(3). Reaction Stereochemistry is a mechanism-based organic reaction software focusing on stereochemistry,  It can track molecular 3D configuration changes in every elementary reaction step.

The demo videos show the basic graphic user interfaces of the software and its basic functionalities.

There are two versions of the software, free version and commercial version. The table below summarizes the major differences between the two versions.

StereoisomerReaction StereochemistryTautomer

Free CommercialFreeCommercialFreeCommercial
conformational isomeronly oneone or moreonly oneone or moreonly oneone or more
configurational isomeronly oneone or moreonly oneone or moreonly oneone or more
reaction set

only oneone or more
user enter Lewis Formulanoyesnoyesnoyes

The free version is listed in Microsoft Store, and can be downloaded at If interested in the commercial version, please contact the developer.