Jonse oxidation;

palladium (II) trifluoroacetate; (+/-)-3,5,3',5'-tBu4Phbox; p-benozquinone T=20°C;

1: 89 percent / PdCl2(PPh3)2, CuI, piperidine / diethyl ether / 4 h / 15 - 20 °C 2: 62 percent / Red-Al / diethyl ether; toluene / 5 h / -20 - 36 °C 3: 1.) methanesulfonyl chloride, triethylamine, 2.) DBU / 1.) CH2Cl2, room temperature, 30 min, 2.) CH2Cl2, room temperature 4: 82 percent / PdCl2(PPh3)2, triethylamine / tetrahydrofuran / 4 h View Scheme