bromine in ethylene glycol

distannoxane 1a in benzene 24 h; Heating;

potassium hydroxide; ammonium chloride; diethylene glycol

1: benzene; toluene-4-sulfonic acid 2: potassium hydroxide; ammonium chloride; diethylene glycol View Scheme

1: 1.) HBr, 2.) NaH / 2.) THF 2: 81 percent / LiAlH4 / tetrahydrofuran / 24 h / Heating 3: 85 percent / pyridine, Cr2O3, kieselguhr / CH2Cl2 / 0.33 h / Ambient temperature 4: 61 percent / silica gel, 15percent H2SO4 / CH2Cl2 / 24 h / Ambient temperature View Scheme

tert.-butylhydroperoxide; potassium carbonate; 20percent Pd(OH)2/C in dichloromethane T=24°C; 72 h;

1.1: 45 percent / n-butyllithium / pentane; hexane / -40 - -30 °C 2.1: potassium tert-butoxide / dimethylsulfoxide / 1.5 h / 90 °C 2.2: 45 percent / H2SO4; water / 0.5 h 3.1: 0.2 g / lithium aluminum hydride / diethyl ether / 0.5 h / 20 °C 4.1: tri-n-butylphosphane / tetrahydrofuran / 1.5 h 5.1: hydrogen peroxide / CDCl3; pyridine / 0.5 h / -20 °C View Scheme

2,6-dimethylpyridine; N-bromosuccinmide; 2,2'-azo-bisisobutyronitrile in tetrachloromethane Irradiation;

1: N-bromosuccinimide 2: 55 percent / NaN3, Adogen 464 / CCl4; H2O / 19 h / Ambient temperature 3: 6 percent / Lindlar catalyst, quinoline, H2 / ethanol / 4.5 h / 760 Torr / Ambient temperature View Scheme