1.1: Dess-Martin periodane / dichloromethane / 1 h / 20 °C 1.2: 48 h 2.1: bis(trichloromethyl) carbonate; 4-methyl-morpholine / dichloromethane / 3.08 h / -78 - -30 °C 3.1: dichloromethane / 72 h / 20 °C 4.1: potassium carbonate; methanol / 0.5 h / 20 °C 4.2: 20 °C View Scheme