# Shi Epoxidation Issues - Any help would be appreciated

As part of my PhD project, I'm currently looking into running a Shi Epoxidation reaction. The first step is to reproduce the current literature on this reaction by using trans-stilbene as my substrate. However, from the multitude of reaction conditions I have tried, none of them seem to work as described in the papers (very low to no conversion observed). I have tried the reaction conditions from the following papers:

1. "An Efficient Asymmetric Epoxidation Method for trans-Olefins Mediated by a Fructose-Derived Ketone" - the original Shi paper - using oxone as oxidant
2. "An Efficient Catalytic Asymmetric Epoxidation Method" - Shi - optimized conditions - using oxone as oxidant
3. "Asymmetric epoxidation using hydrogen peroxide ($$\ce{H2O2}$$) as primary oxidant" - Shi - using hydrogen peroxide as oxidant

The catalyst I have used in my reactions is the Shi Diketal Catalyst purchased from Sigma (https://www.sigmaaldrich.com/catalog/product/aldrich/520160?lang=en&region=CA). What I've tried so far:

1. testing different batches of oxone, including titrating it and running test reactions ($$\ce{aldehyde -> COOH}$$ oxidation) - > 90% conversion observed
2. trans-stilbene + m-CPBA -> oxidized product is quantitative
3. I've left reactions run for > $$\pu{6-24 h}$$ with low conversion observed (< 30%).
4. $$\mathrm{^{13}C}$$ and $$\mathrm{^{1}H}$$ NMR of the catalyst show that it's clean

I am slowly running out of things to try out. It's weird because it's a published and highly used reaction ... If you have any experience with this reaction I would really appreciate your help!

• What pH are you running your reactions at? – Waylander Aug 20 '19 at 9:20
• Please add proper citations to the papers so that they are easier to find. – Martin - マーチン Aug 20 '19 at 14:01