camphor-10-sulfonic acid in dichloromethane T=23°C; 12 h; Yield given;

<b>Multi-step reaction with 5 steps<br /> </b>1: p-TsOH / 12 h / 23 &deg;C<br />2: 1.) (COCl)2, DMSO, 2.) NEt₃ <br />3: camphorsulfonic acid<br />4: O₃ <br />5: NaBH₄ / ethanol / 0 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 1.) (COCl)2, DMSO, 2.) NEt₃ <br />2: camphorsulfonic acid<br />3: O₃ <br />4: NaBH₄ / ethanol / 0 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1: LiAlH₄ / diethyl ether<br />2: p-TsOH / 12 h / 23 &deg;C<br />3: 1.) (COCl)2, DMSO, 2.) NEt₃ <br />4: camphorsulfonic acid<br />5: O₃ <br />6: NaBH₄ / ethanol / 0 &deg;C<br /> <br /> &nbsp;