1: Amberlyst-15 / methanol / 25 °C 2: tetrahydrofuran / 24 h / -78 deg C to 0 deg C 3: SnCl4 / 1 h / -78 °C 4: 20 percent / Bu4NF / tetrahydrofuran View Scheme

1: 1) BH3*THF, 2) pyridinium chlorochromate / 1) 25 deg C, 2) CH2Cl2, 25 deg C 2: Amberlyst-15 / methanol / 25 °C 3: tetrahydrofuran / 24 h / -78 deg C to 0 deg C 4: SnCl4 / 1 h / -78 °C 5: 20 percent / Bu4NF / tetrahydrofuran View Scheme

tetrabutyl ammonium fluoride in tetrahydrofuran Ambient temperature;

1: tetrahydrofuran / 24 h / -78 deg C to 0 deg C 2: SnCl4 / 1 h / -78 °C 3: 20 percent / Bu4NF / tetrahydrofuran View Scheme

1: SnCl4 / 1 h / -78 °C 2: 20 percent / Bu4NF / tetrahydrofuran View Scheme

tetrabutyl ammonium fluoride in tetrahydrofuran