1: pyridinium chlorochromate, sodium acetate / CH2Cl2 / 1.5 h 2: tetrahydrofuran; diethyl ether / -78 °C 3: 86 percent / pyridinium chlorochromate, sodium acetate / CH2Cl2 / 1.5 h 4: 52 percent / p-toluenesulfonic acid / 7 h / Heating 5: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C 2.) THF, hexane, 0 deg C View Scheme

1: tetrahydrofuran; diethyl ether / -78 °C 2: 86 percent / pyridinium chlorochromate, sodium acetate / CH2Cl2 / 1.5 h 3: 52 percent / p-toluenesulfonic acid / 7 h / Heating 4: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C 2.) THF, hexane, 0 deg C View Scheme

1: 86 percent / pyridinium chlorochromate, sodium acetate / CH2Cl2 / 1.5 h 2: 52 percent / p-toluenesulfonic acid / 7 h / Heating 3: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C 2.) THF, hexane, 0 deg C View Scheme

1: 52 percent / p-toluenesulfonic acid / 7 h / Heating 2: 1.) n-butyllithium / 1.) THF, hexane, -78 deg C 2.) THF, hexane, 0 deg C View Scheme

n-butyllithium 1.) THF, hexane, -78 deg C 2.) THF, hexane, 0 deg C; Yield given. Multistep reaction;

n-butyllithium; toluene-4-sulfonic acid 1.) benzene, 2.) THF, -78 deg C to 21 deg C; Yield given. Multistep reaction;

2,3,5-trimethyl-pyridine; PPh3.Br2 in dichloromethane T=0°C; 0.25 h;

1: 1.) n-butyllithium, HMPA / 1.)THF, hexane, -78 degC to 0 degC 2.) 45-50 degC, 2 h 2: 63 percent / 5percent HCl / tetrahydrofuran; H2O / 2 h / 50 °C View Scheme