dimercaptoethane; camphor-10-sulfonic acid in dichloromethane Ambient temperature; Yield given;

<b>Multi-step reaction with 4 steps<br /> </b>1: 1.) TMSTf; 2.) NaOH / 1.) CH₂Cl₂, -78 deg C; 2.) MeOH, 0 deg C<br />2: 93 percent / TEBA-Cl, 30percent aq. sodium hydroxide / CH₂Cl₂ / 18 h / Ambient temperature<br />3: dimethylformamide / 3 h / Ambient temperature<br />4: Raney nickel / aq. ethanol / 12 h / Ambient temperature<br /> <br /> &nbsp;