1.1: ozone / dichloromethane / -78 °C / Inert atmosphere 1.2: -78 - 20 °C / Inert atmosphere 2.1: ammonium acetate; acetic acid / tetrahydrofuran / 0.25 h / 170 °C / Inert atmosphere; Molecular sieve; Microwave irradiation View Scheme

1: With ozone in dichloromethane T=-78°C; Inert atmosphere; 2: With triphenylphosphine in dichloromethane T=-78 - 20°C; Inert atmosphere;