1: air / chromatography on SiO2 2: 170 mg / CHCl3 / 168 h / Ambient temperature; in the dark View Scheme

1: 1.) 1,2-dibromoethane, magnesium / 1.) benzene, THF, 2.) -45 deg C -> room temperature, 15 min 2: air / chromatography on SiO2 3: 170 mg / CHCl3 / 168 h / Ambient temperature; in the dark View Scheme

hydrogen; palladium on activated charcoal in ethanol Ambient temperatureatmospheric pressure;

in chloroform 168 h; Ambient temperaturein the dark;

tert.-butylhydroperoxide; cobalt(II) 4-methylbenzoate in benzene 12 h;