potassium carbonate; N-benzyl-N,N,N-triethylammonium chloride in dichloromethane; benzene T=20°C;

1: 2-(methylthio)cyclopentanone With potassium hexamethylsilazane in tetrahydrofuran T=-78°C; 0.333333 h; 2: N,N-bis(trifluoromethanesulfonyl)aniline in tetrahydrofuran T=-78°C; 0.333333 h; 3: With 2,6-dimethylpyridine in dimethyl sulfoxide T=80°C; 2 h; Further stages.;

1: 81 percent / H2O2; SeO2 2: 65 percent / K2CO3 / benzyltriethylammonium chloride / benzene; CH2Cl2 / 20 °C View Scheme

1: 85 percent / TsOH*H2O / benzene / 43 h / Heating; azeotropic removal of water View Scheme

Yield given. Multistep reaction;