1: 91 percent / hexachloroacetone, triphenylphosphine / tetrahydrofuran / 0.5 h / -78 °C 2: CsF View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: lithium, naphthalene / tetrahydrofuran / 3 h / -30 &deg;C<br />2: 64 percent / 12 h / -78 - 23 &deg;C<br /> <br /> &nbsp;