1: 5percent H2SO4-AcOH / tetrahydrofuran / 3 h / Heating 3: 1.) H2, 5percent HCl, 2.) O3 / 1.) r.t., 4 d 4: 1.) O3, 2.) Me2S 5: sulphamic acid, sodium chlorite 6: H2SO4 / acetone 7: 52 percent / AlCl3, Me2S / CH2Cl2 / -10 °C 8: 68 percent / 5percent HCl / acetone / 24 h / 55 °C View Scheme

1: 73 percent / ccHCl / acetic acid / 24 h / Ambient temperature 2: 89 percent / Me2S, BF3*OEt2 / CH2Cl2 / 42 h / Ambient temperature 3: 69 percent / aq.NaHCO3 / methanol / 6 h / Ambient temperature 4: 1.) O3, oil violet; 2.) dimethyl sulphide / 1.) EtOH, -75 degC; 2.) EtOH, 30 min. 5: 66 percent / sulphamic acid, sodium chlorite / CH2Cl2; H2O / 24 h / Ambient temperature 6: 69 percent / Me2S, AlCl3 / CH2Cl2 / 15 h / Ambient temperature View Scheme