zinc(II) permanganate; silica gel in dichloromethane T=60°C; 13 h;

tetra-(n-butyl)ammonium iodide in dichloromethane T=25°C; sulfonation; 16 h;

triethylamine in dichloromethane

1: pyrrolidin-2-one With sodium hydride in tetrahydrofuran; mineral oil 1 h; Inert atmosphere; 2: benzenesulfonyl chloride in tetrahydrofuran; mineral oil 1 h; Inert atmosphere;