tin(IV) chloride in tetrahydrofuran 1.5 h;

1: triethylamine / tetrahydrofuran 2: dicyclohexylcarbodiimide / dimethylaminopyridine 3: HClO4 4: dicyclohexylcarbodiimide / dimethylaminopyridine 5: SnCl4 / tetrahydrofuran View Scheme

1: dicyclohexylcarbodiimide / dimethylaminopyridine 2: SnCl4 / tetrahydrofuran View Scheme

1: dicyclohexylcarbodiimide / dimethylaminopyridine 2: HClO4 3: dicyclohexylcarbodiimide / dimethylaminopyridine 4: SnCl4 / tetrahydrofuran View Scheme

1: dicyclohexylcarbodiimide / dimethylaminopyridine 2: HClO4 3: dicyclohexylcarbodiimide / dimethylaminopyridine 4: SnCl4 / tetrahydrofuran View Scheme

1: N-ethyldiisopropylamine / CH2Cl2 / 48 h / Ambient temperature 2: 6.6 aq. N KOH / ethanol / 12 h / Heating 3: dicyclohexylcarbodiimide, 4-(dimethylamino)pyridine / CH2Cl2 / 1 h / Ambient temperature 4: 76 percent / SnCl4 / tetrahydrofuran / 1.5 h View Scheme

1: dicyclohexylcarbodiimide, 4-(dimethylamino)pyridine / CH2Cl2 / 1 h / Ambient temperature 2: 76 percent / SnCl4 / tetrahydrofuran / 1.5 h View Scheme

1: 30 percent / dicyclohexylcarbodiimide, 4-(dimethylamino)pyridine / CH2Cl2 / 3 h / Ambient temperature 2: HClO4 / methanol / 0.83 h / Ambient temperature 3: dicyclohexylcarbodiimide, 4-(dimethylamino)pyridine / CH2Cl2 / 1 h / Ambient temperature 4: 76 percent / SnCl4 / tetrahydrofuran / 1.5 h View Scheme