1: With n-butyllithium in tetrahydrofuran T=-78°C; 2: With lithium; ethylamine in tetrahydrofuran Further stages.;

<b>Multi-step reaction with 2 steps<br /> </b>1: BF₃*Et₂O / CH₂Cl₂ / 2 h / -78 &deg;C<br />2: Bu₄NF / tetrahydrofuran / 23 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: BF₃*Et₂O / CH₂Cl₂; methanol / 0.17 h / 20 &deg;C<br />1.2: 97 percent / CH₂Cl₂; methanol / 1 h / -78 &deg;C<br />2.1: BF₃*Et₂O / CH₂Cl₂ / 2 h / -78 &deg;C<br />3.1: Bu₄NF / tetrahydrofuran / 23 &deg;C<br /> <br /> &nbsp;