1: 89 percent / TsOH / benzene / 63 h / Heating; azeotropic removal of water View Scheme

1: With 3,3-dimethyldioxirane in acetone T=20°C; Epoxidation; 8 h; 2: With Amberlyst 15; sodium bromide in acetone T=20°C; Bromination; 12 h;

tert.-butylhydroperoxide; sodium chlorite in water; acetonitrile T=50°C; 17 h; Inert atmosphereMolecular sieve; regioselective reaction;

1: 94 percent / NaHCO3 / H2O / 18 h 2: Br2 / CCl4 / 0.5 h / 10 - 15 °C 3: NaHCO3/H2O / H2O View Scheme

hydrogenchloride; N-bromosuccinmide; sulfuric acid 1.) 20 deg C, 1.5 h; 2.) CH2Cl2, r.t., 20 h; Yield given. Multistep reaction;

toluene-4-sulfonic acid in benzene 63 h; Heatingazeotropic removal of water;

1: methyllithium; 2-bromo-3-methyl-2-cyclopenten-1-one in tetrahydrofuran T=-78°C; 2 h; 2: With tert.-butyl lithium in tetrahydrofuran T=-78°C; 2 h; 3: formaldehyd; methyl iodide With p-methylbenzenesulfonyl (tosylate); sodium hydride more than 3 stages;

potassium carbonate; tetrakis(triphenylphosphine) palladium(0) in water; toluene T=90°C; Suzuki-Miyaura cross-coupling; 1.8 h;

1.1: 81 percent / triethyl orthoformate; p-toluenesulfonic acid monohydrate / 4 h / 20 °C 2.1: nBuLi / tetrahydrofuran / 1 h / -78 °C 2.2: 86 percent / tetrahydrofuran / 2 h / -78 °C 3.1: 4.60 g / p-toluenesulfonic acid monohydrate / CH2Cl2 / 2 h / 20 °C 4.1: diethyl ether 4.2: HCl; water / 0.05 h 4.3: 72 percent / NaH / tetrahydrofuran; methanol / 3 h / 20 °C View Scheme

1.1: 81 percent / triethyl orthoformate; p-toluenesulfonic acid monohydrate / 4 h / 20 °C 2.1: nBuLi / tetrahydrofuran / 1 h / -78 °C 2.2: 86 percent / tetrahydrofuran / 2 h / -78 °C View Scheme