dipyridinium dichromate in N,N-dimethyl-formamide T=20°C; 12 h; Molecular sieve;

<b>Multi-step reaction with 5 steps<br /> </b>1: triethylamine; dmap / N,N-dimethyl-formamide<br />2: potassium <i>tert</i>-butylate / tetrahydrofuran<br />3: triethylamine; sulfur trioxide pyridine complex / dichloromethane<br />4: tetrahydrofuran / -78 &deg;C<br />5: Grubb's 2nd generation catalyst / dichloromethane / |Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: tetrahydrofuran / -78 &deg;C<br />2: Grubb's 2nd generation catalyst / dichloromethane / |Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1: sulfuric acid<br />2: triethylamine; dmap / N,N-dimethyl-formamide<br />3: potassium <i>tert</i>-butylate / tetrahydrofuran<br />4: triethylamine; sulfur trioxide pyridine complex / dichloromethane<br />5: tetrahydrofuran / -78 &deg;C<br />6: Grubb's 2nd generation catalyst / dichloromethane / |Reflux<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: triethylamine; sulfur trioxide pyridine complex / dichloromethane<br />2: tetrahydrofuran / -78 &deg;C<br />3: Grubb's 2nd generation catalyst / dichloromethane / |Reflux<br /> <br /> &nbsp;