The free-radical nature of manganese(V) oxidation is also evident in the olefin epoxidation (Scheme 6).
Epoxidation of cis-stilbene gave a 1.6:1 mixture of trans- and cis-epoxide, respectively,in 88% overall yield, clearly indicating a loss of stereochemistry at the double bond.
This in turn suggested that the addition of the (porphinato)manganese(V) complex to the double bond will result in a freely rotating free radical intermediate.