1: With oxalyl dichloride; dimethyl sulfoxide in dichloromethane T=-60 - -50°C; 0.333333 h; 2: With triethylamine in dichloromethane T=-60 - 20°C; 0.0833333 h;

1: 51 percent / polyphosphoric acid / 0.67 h / 90 - 100 °C 2: N-bromoacetamide, AcOH / 3 h / Ambient temperature 3: 79 percent / MeONa / tetrahydrofuran / 4 h / Ambient temperature 4: N-bromosuccinimide, azoisobutyronitrile / CCl4 / 0.67 h / 60 - 70 °C 5: 62 percent / MeONa / tetrahydrofuran / 1) 0 deg C, 1 h, 2) rt, 3 h 6: trifluoroacetic acid / CDCl3 View Scheme

1: With acetic anhydride 1.5 h; Heating / reflux; 2: With hydrogenchloride; water 5 h; Heating / reflux; 3: With sodium hydroxide in water pH=7;

sodium tetrahydroborate

1: 98 percent / H2O2, AcOH / 4 h / 70 - 80 °C 2: 0.5 h / Heating 3: NaOH / methanol / 2 h / Ambient temperature View Scheme

hydrogenchloride Heating;

1: 51 percent / polyphosphoric acid / 0.67 h / 90 - 100 °C 2: N-bromoacetamide, AcOH / 3 h / Ambient temperature 3: 79 percent / MeONa / tetrahydrofuran / 4 h / Ambient temperature 4: N-bromosuccinimide, azoisobutyronitrile / CCl4 / 0.67 h / 60 - 70 °C 5: 62 percent / MeONa / tetrahydrofuran / 1) 0 deg C, 1 h, 2) rt, 3 h 6: 27 percent / KOH / H2O; 2-methyl-propan-2-ol / 168 h / Ambient temperature View Scheme