1: potassium hexamethylsilazane / tetrahydrofuran / -78 °C 2: tetrakis(triphenylphosphine) palladium(0); sodium carbonate / ethylene glycol dimethyl ether 3: methanol / Photolysis; Inert atmosphere 4: dipyridinium dichromate / dichloromethane 5: hydrogenchloride / acetone 6: dipyridinium dichromate / dichloromethane View Scheme