1: With ozone in methanol; dichloromethane T=-78°C; ozonolysis; 2: With dimethylsulfide; sodium hydrogencarbonate in methanol; dichloromethane Reduction; 6 h; 3: With ammonium hydroxide in methanol; dichloromethane Cyclization; 15 h; Further stages.;

sulfuric acid T=140 - 150°C; 0.5 h;

1: 100 percent / benzene / Heating 2: concd. H2SO4 / 0.5 h / 140 - 150 °C View Scheme

sulfuric acid; phosphorus pentoxide T=150°C;

T=750°C; Rearrangement; Further byproducts given;

diborane in tetrahydrofuran 2.5 h; Heating;