Integration of electrooxidative cyclization and chemical oxidation via alkoxysulfonium ions. Synthesis of exocyclic ketones from alkenes with cyclization.

An integration of electrooxidative cyclization and chemical oxidation was achieved. Electrochemical oxidation of alkenes having a nucleophilic moiety in the presence of DMSO gave cyclized alkoxysulfonium ions, which were converted to the corresponding ketones by treatment with triethylamine in a one-pot sequential manner. The method is also an effective tool for cyclization of 1,6-dienes affording five-membered ring diketones in high stereoselectivity.