methanol Heating;

<b>Multi-step reaction with 2 steps<br /> </b>1: 86 percent / n-BuLi / tetrahydrofuran; hexane / 2 h / 0 &deg;C<br />2: 95 percent / trimethylsilyl trifluoromethanesulfonate / CH₂Cl₂ / 1 h / 25 - 30 &deg;C<br /> <br /> &nbsp;