1: 92 percent / Bu3SnH; AIBN / toluene / 2.5 h / Heating 2: 57 percent / oxalic acid; silica gel 3: 93 percent / AcOH; AcONH4; air / 1.5 h / Heating View Scheme

<b>Multi-step reaction with 4 steps<br /> </b>1: 54 percent / ethanol / 4 h / Heating<br />2: 54 percent / p-TsOH / toluene / 8 h / Heating<br />3: 54 percent / dimethylethylene urea; t-BuOK / toluene / Heating<br />4: 83 percent / 2,6-lutidine; dilauroyl peroxide / cyclohexane / Heating<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: 89 percent / acetone / 20 &deg;C<br />2: 83 percent / 2,6-lutidine; dilauroyl peroxide / cyclohexane / Heating<br /> <br /> &nbsp;