1.1: O3/O2 / methanol / -78 - 0 °C 1.2: 70 percent / thiourea / methanol / 3 h 2.1: I2 / toluene / Heating View Scheme

1.1: O3/O2 / methanol / -78 - 0 °C 1.2: 70 percent / thiourea / methanol / 3 h 2.1: 72 percent / I2 / toluene / Heating 3.1: methanol / 2 h / Heating 3.2: 78 percent / Ba(OH)2 / methanol; H2O / 24 h / Heating View Scheme

1: With oxygen; ozone in methanol T=-78 - 0°C; 2: With thiourea in methanol 3 h;