boron trifluoride diethyl etherate in diethyl ether T=0 - 20°C; Yield given;

<b>Multi-step reaction with 2 steps<br /> </b>1: 1.) Cp₂Ti&lt;P(OEt)3&gt;2 / 1.) THF, 15 min, 2.) THF, reflux, 1 h<br />2: MCPBA / CH₂Cl₂ / 1.5 h / 0 - 20 &deg;C<br /> <br /> &nbsp;