1: 85 percent / 20 percent H2SO4, silica gel (Merck 60, 70-230 mesh) / CH2Cl2 / 6 h / Ambient temperature 2: hexane / 6 h / Ambient temperature; Irradiation View Scheme

1: 76 percent / 4-(N,N-dimethylamino)pyridine, N,N'-dicyclohexylcarbodiimide / CHCl3 / 0.25 h / Ambient temperature 2: 85 percent / 20 percent H2SO4, silica gel (Merck 60, 70-230 mesh) / CH2Cl2 / 6 h / Ambient temperature 3: hexane / 6 h / Ambient temperature; Irradiation View Scheme

sulfuric acid; silica gel in dichloromethane 6 h; Ambient temperature; Yield given. Title compound not separated from byproducts;

in hexane 6 h; Ambient temperatureIrradiation; Yield given. Yields of byproduct given. Title compound not separated from byproducts;