in cyclohexane Irradiation (UV/VIS); irradiation with a low-pressure mercury lamp for 5 h at room temp.; preparative TLC (silica gel, benzene/hexane); spectral data are identical with those of authentic samples;

in toluene reflux, 20 h; preparative TLC (silica gel, benzene/hexane);

in cyclohexane Irradiation (UV/VIS); irradiation with a low-pressure mercury lamp for 5 h at room temp.; preparative TLC (silica gel, benzene/hexane); spectral data are identical with those of authentic samples;