boron trifluoride diethyl etherate in benzene 4 h; Heating;

1: 85 percent / CH2Cl2 / 16 h / Ambient temperature 2: 1percent HCl / tetrahydrofuran; H2O / 4 h / 0 °C 3: PCC / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

<b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '2037554', constants.ctx, '0')">sulfuric acid</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '3535376', constants.ctx, '0')">sulfur trioxide</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '4921294', constants.ctx, '0')">sulfur</a> <br /> <br /> &nbsp;