in hexane 6 h; Ambient temperatureIrradiation;

sulfuric acid; silica gel in chloroform 6 h;

1: 68 percent / 4-dimethylaminopyridine, N,N'-dicyclohexylcarbodiimide / CHCl3 / 0.25 h / Ambient temperature 2: 90 percent / 20percent H2SO4, SiO2 / CHCl3 / 6 h View Scheme

1: 10 percent NaOH / 1 h / Heating 2: 68 percent / 4-dimethylaminopyridine, N,N'-dicyclohexylcarbodiimide / CHCl3 / 0.25 h / Ambient temperature 3: 90 percent / 20percent H2SO4, SiO2 / CHCl3 / 6 h View Scheme

1: p-toluenesulphonic acid / benzene / Heating 2: 10 percent NaOH / 1 h / Heating 3: 68 percent / 4-dimethylaminopyridine, N,N'-dicyclohexylcarbodiimide / CHCl3 / 0.25 h / Ambient temperature 4: 90 percent / 20percent H2SO4, SiO2 / CHCl3 / 6 h View Scheme

1: 68 percent / 4-dimethylaminopyridine, N,N'-dicyclohexylcarbodiimide / CHCl3 / 0.25 h / Ambient temperature 2: 90 percent / 20percent H2SO4, SiO2 / CHCl3 / 6 h View Scheme

1: 17 percent / hexane / 6 h / Ambient temperature; Irradiation 2: H2SO4 / acetic acid / 0.5 h / Heating View Scheme