N-cyclohexylcarbodiimide N-methyl polystyrene in dichloromethane T=20°C; 10 h;

sodium hydride 1.) THF, 0 deg C, 15 min; 2.) THF, r.t., 2 h; Yield given. Multistep reaction;

1: SOCl2 / benzene; dimethylformamide / 5 h / 20 °C 2: Et3N / tetrahydrofuran / 2 h View Scheme

tributylphosphine in xylene 2 h; Ambient temperature;

1: NaI; TMSCl / acetonitrile / 0.25 h / 20 °C 2: 52 percent / NBS; benzoyl peroxide / CCl4 / 5 h / Heating View Scheme

1: NaI; TMSCl / acetonitrile / 0.25 h / 20 °C 2: 52 percent / NBS; benzoyl peroxide / CCl4 / 5 h / Heating 3: 90 percent / 18-crown-6 / acetonitrile / 1 h / 20 °C 4: lipase PS / acetonitrile / 7 h / 20 °C / pH 7.0 5: NaOH / H2O; methanol; ethyl acetate / 0.25 h / 0 °C View Scheme