1: pyridine; trimethylsilyl iodide / sulfolane / 20 h / 70 °C / |Inert atmosphere 2: anhydrous iron chloride; tert.-butylhydroperoxide; pyridine-2,6-dicarboxylate N-oxide / water; 1,1-dimethylpropan-1-ol / 8 h / 20 °C / |Cooling with ice View Scheme