Abnormal Ito-Saegusa oxidation of TIPS enol ether assisted by a hydroxy group on a side chain

Although Ito-Saegusa oxidation gives defined α,β-unsaturated ketones from silyl enol ether of ketones controlled by the position of the sp2 carbon of the silyl enol ether, the formation of a regioisomeric product that was oxidized abnormally was observed. The structural requirements for the substrates, the conditions, and a plausible mechanism are presented.