boron trifluoride diethyl etherate Yield given;

<b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '1696847', constants.ctx, '0')">dimethylsulfide</a>;&nbsp;<a href="#" onclick="return RXDsubstances(event, this, '4921393', constants.ctx, '0')">ozone</a> <br />&nbsp;1.) CH₂Cl₂, -78 deg C, 15 min, 2.) CH₂Cl₂, -78 deg C, 20 min;&nbsp;&nbsp;Yield given. Multistep reaction;&nbsp;<br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: NaOH / dimethylformamide<br />2: 2,6-lutidine / CH₂Cl₂ <br />3: Bu₄NHSO₄, butyllithium / tetrahydrofuran / -78 &deg;C<br />4: O₃, dimethyl sulfide, Sudan red 7B / CH₂Cl₂ / -78 &deg;C<br /> <br /> &nbsp;