titanium tetrachloride 18 h; 1.) -78 degC, 2.) -10 to 0 degC;

<b>Multi-step reaction with 3 steps<br /> </b>1: 50 percent / thermolysis<br />2: 63 percent / MoO₅, HMPA, H₂O / CH₂Cl₂ / 0 degC to r.t.<br />3: 64 percent / Cs₂CO₃ / dimethylformamide / 30 h / 50 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: 63 percent / MoO₅, HMPA, H₂O / CH₂Cl₂ / 0 degC to r.t.<br />2: 64 percent / Cs₂CO₃ / dimethylformamide / 30 h / 50 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: 50 percent / thermolysis<br />2: 63 percent / MoO₅, HMPA, H₂O / CH₂Cl₂ / 0 degC to r.t.<br />3: 64 percent / Cs₂CO₃ / dimethylformamide / 30 h / 50 &deg;C<br /> <br /> &nbsp;