Oxidative bridgehead functionalization of (4 + 3) cycloadducts obtained from oxidopyridinium ions.

Treatment of selected (4 + 3) cycloadducts derived from oxidopyridinium ions with N -iodosuccinimide (NIS) in hexafluoroisopropanol (HFIP) resulted in the formation of bridgehead ethers via a net oxidative C-H activation.