1: 78 percent / triethyl amine / dimethylformamide / 24 h / Heating 2: 1.) titanium tetrachloride, 2.) p-toluenesulfonic acid / 1.) dichloromethane, room temp., 16 h, 2.) benzene, distillation 3: 1.) phosphorus pentachloride, 2.) potassium tert-butoxide / 1.) ether, reflux, 24 h, 2.) tert-butanol, reflux, 24 h View Scheme

1: 1.) titanium tetrachloride, 2.) p-toluenesulfonic acid / 1.) dichloromethane, room temp., 16 h, 2.) benzene, distillation 2: 1.) phosphorus pentachloride, 2.) potassium tert-butoxide / 1.) ether, reflux, 24 h, 2.) tert-butanol, reflux, 24 h View Scheme

sodium methylate; ozone; tetrachloroethane, 1,1,2,2- in chloroform-d1 1.) -60 deg C; 2.) to r.t.;

sodium methylate; ozone; tetrachloroethane, 1,1,2,2- in chloroform-d1 1.) -60 deg C; 2.) to r.t.;

sodium methylate; ozone; tetrachloroethane, 1,1,2,2- in chloroform-d1 1.) -60 deg C; 2.) to r.t.;