hydrogenchloride 48 h; Ambient temperature;

<b>Multi-step reaction with 5 steps<br /> </b>1: tetrahydrofuran; toluene / 7 h / 45 &deg;C<br />2: 1.) NEt₃ / 1.) CHCl₃; 2.) CHCl₃, THF, 4 h, -70 deg C then 1 h, room temp.<br />3: toluene / 20 h / Heating<br />4: 83 percent / CH₂Cl₂ / 3.5 h / Ambient temperature<br />5: 1.) 1.37 M n-BuLi / 1.) hexane, THF, 20 min, -70 deg C; 2.) hexane, THF, 12 h, -70 deg C<br /> <br /> &nbsp;