A study, via isotopic labeling, of the stereoselective processes in a Shi-type epoxidation, has revealed that the chiral platform provided by the catalyst mediates the transfer of the pro-S “O” of the related dioxirane species to the alkene in a doubly stereoselective manner.
![Dioxirane mediated asymmetric epoxidations: Stereochemical studies via isotopic labeling](https://www.iciq.org/wp-content/uploads/2014/03/Dioxirane-mediated-asymmetric_eng_noticies_articles_2008_71.gif)