acetic acid; dichloro bis(acetonitrile) palladium(II) in acetonitrile T=60 - 80°C;

1: n-bromopentane With magnesium in diethyl ether T=20°C; 1 h; 2: cyclopent-2-enone in diethyl ether T=20°C; 2 h; 3: With Celite; water; ammonium chloride; pyridinium chlorochromate more than 3 stages;

1: 94 percent / 12 N aq. HCl / ethanol / 5 h / Ambient temperature 2: p-toluenesulfonic acid / benzene / 4 h / Heating 3: m-chloroperbenzoic acid / CH2Cl2 / 1.) 0 deg C, 1 h, 2). RT, 4 h 4: 1.) sodium hydride / 1.) DMF, RT, 2.) DMF, 70 deg C, 20 h 5: sodium hydride, potassium hydride / dimethylsulfoxide / Ambient temperature 6: pyridinium p-toluenesulfonate, water / acetone / 10 h / Heating View Scheme

1: p-toluenesulfonic acid / benzene / 4 h / Heating 2: m-chloroperbenzoic acid / CH2Cl2 / 1.) 0 deg C, 1 h, 2). RT, 4 h 3: 1.) sodium hydride / 1.) DMF, RT, 2.) DMF, 70 deg C, 20 h 4: sodium hydride, potassium hydride / dimethylsulfoxide / Ambient temperature 5: pyridinium p-toluenesulfonate, water / acetone / 10 h / Heating View Scheme

1: 1.) sodium hydride / 1.) DMF, RT, 2.) DMF, 70 deg C, 20 h 2: sodium hydride, potassium hydride / dimethylsulfoxide / Ambient temperature 3: pyridinium p-toluenesulfonate, water / acetone / 10 h / Heating View Scheme

1: sodium hydride, potassium hydride / dimethylsulfoxide / Ambient temperature 2: pyridinium p-toluenesulfonate, water / acetone / 10 h / Heating View Scheme

methanesulfonic acid; phosphorus pentoxide T=60°C; 1-2 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: m-chloroperbenzoic acid / CH2Cl2 / 1.) 0 deg C, 1 h, 2). RT, 4 h 2: 1.) sodium hydride / 1.) DMF, RT, 2.) DMF, 70 deg C, 20 h 3: sodium hydride, potassium hydride / dimethylsulfoxide / Ambient temperature 4: pyridinium p-toluenesulfonate, water / acetone / 10 h / Heating View Scheme

1: 96 percent / bromine / diethyl ether 2: 85 percent / potassium t-butoxide / dimethylsulfoxide / 3 h / Ambient temperature 3: 1 percent Chromat. / 85percent phosphoric acid, 90percent formic acid / 3 h / 90 °C View Scheme

1: 85 percent / potassium t-butoxide / dimethylsulfoxide / 3 h / Ambient temperature 2: 1 percent Chromat. / 85percent phosphoric acid, 90percent formic acid / 3 h / 90 °C View Scheme