pyridinium chlorochromate in dichloromethane T=60 - 70°C; 24 h;

1: (CH3)3COK / dimethylsulfoxide / 3 h / Ambient temperature 2: 60 percent / pyridinium chlorochromate / CH2Cl2 / 24 h / 60 - 70 °C View Scheme

1: 65 percent / LDA / hexamethylphosphoric acid triamide / 18 h / -70 °C 2: 72 percent / LHMDS / tetrahydrofuran / 1 h / -70 °C 3: 91 percent / 30percent H2O2 / 0.33 h / 0 deg C to r.t. View Scheme

1: 72 percent / LHMDS / tetrahydrofuran / 1 h / -70 °C 2: 91 percent / 30percent H2O2 / 0.33 h / 0 deg C to r.t. View Scheme

1: MCPBA / CH2Cl2 / 3 h / 20 °C 2: DBU / CH2Cl2 / 1 h / 20 °C View Scheme