diisobutylaluminium hydride in dichloromethane; toluene T=-78°C; 1 h;

<b>Multi-step reaction with 3 steps<br /> </b>1.1: potassium hydroxide / dimethyl sulfoxide / 2 h / 0 &deg;C<br />2.1: oxalyl dichloride; dimethyl sulfoxide / dichloromethane / 0.5 h / -78 &deg;C<br />2.2: 20 &deg;C<br />3.1: toluene / 5 h / 20 &deg;C<br /> <br /> &nbsp;