in AcOH-d4 3 h; Heating / reflux;

water; sodium hydroxide T=20°C; 2 h;

1: 97 percent / bromine / CHCl3; CCl4 / 1 h / 20 °C 2: 40 percent / calcium alginate; citrate-phosphate buffer; aq. ammonia / glucose; Saccharomyces cerevisiae / ethanol / 24 h / 30 °C / pH 4.0 3: 86 percent / CaCl2; potassium carbonate / ethanol / 9.5 h 4: 98 percent / BF3*Et2O / 4 h / 20 °C 5: 98 percent / HCl / 1.5 h / 20 °C View Scheme

p-toluenesulfonic acid monohydrate; acetic anhydride

1: potassium bi carbonate 2: water View Scheme

Multi-step reaction with 2 steps 1: sodium azide / dimethylformamide / 2.5 h / 25 °C2: 94 percent Chromat. / ethanol, n-butyllithium / 1) hexane, THF, 25 deg C, 2) 45 min, 25 deg C