toluene-4-sulfonic acid in benzene 60 h; Heating / reflux;

1: 97.4 percent / tetrahydrofuran / 2 h / -78 °C 2: 91 percent / 30percent H2O2, CH3COOH / tetrahydrofuran; H2O / 2 h / -25 - -20 °C 3: 98 percent / p-toluenesulfonic acid / benzene / 2 h / Heating 4: 1.) Me2CuLi, 2.) NH4OH/H2O / 1.) ether, -60 deg C to 0 deg C View Scheme

1: 91 percent / 30percent H2O2, CH3COOH / tetrahydrofuran; H2O / 2 h / -25 - -20 °C 2: 98 percent / p-toluenesulfonic acid / benzene / 2 h / Heating 3: 1.) Me2CuLi, 2.) NH4OH/H2O / 1.) ether, -60 deg C to 0 deg C View Scheme

2: TsOH / toluene / Heating View Scheme

1: 1.) BF3-Et2O/diglyme, NaBH4/diglyme; 2.) CrO3 / 1.) ether, 1 h; 2.) pyridine, 24 h, RT 2: 73 percent / pyridine; ethanol / 24 h / Ambient temperature 3: 24 percent / 0.5 N NaOCH3 / methanol / 4 h / Irradiation View Scheme