1: 3-(benzyloxycarbonyl)propionic acid With sodium hydrogencarbonate; tetra-n-butyl-ammonium sulfate in dichloromethane; water T=0°C; 0.25 h; 2: chloromethyl chlorosulphate in dichloromethane; water T=0 - 20°C; 5.5 h;

tetra(n-butyl)ammonium hydroxide in 1,4-dioxane; dichloromethane; toluene

sulfuryl dichloride in dichloromethane

1: 88 percent / cesium carbonate / dimethylformamide / 20 - 70 °C 2: 70 percent / sulfuryl chloride / CH2Cl2 View Scheme

sulfuryl dichloride; cis-4-cyclohexene-1,2-dicarboxylic acid 1.) CH2Cl2, room temperature, 1 h, 2.) 1 h; Yield given. Multistep reaction;