Stereospecific Epoxidation of 2-Hexene with Molecular Oxygen on Photoirradiated Titanium Dioxide Powder

Abstract
Photocatalytic oxidation of 2-hexene on TiO2 powder was investigated under a stream of oxygen gas. The main product was 2,3-epoxyhexane with the chemical yield ranging from 65% to 83% depending on the TiO2 powders. When trans-2-hexene was used as the starting material, the epoxide was also trans. On the other hand, cis epoxide was the chief product from cis-2-hexene. From mixed 2-hexene (trans/cis = 1.7), larger amounts of trans epoxide were obtained than cis-epoxide in the initial period of the reaction, indicating that trans-2-hexene is more reactive than the cis isomer on the photocatalyst.