palladium diacetate; 1,2-bis-(diphenylphosphino)ethane in acetonitrile 1 h; Heating;

1: With hydroquinone T=45°C; addition-elimination; 40 h; 2: With acetic acid in tetrahydrofuran Hydrolysis; 3 h;

2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride in benzene 2 h; Heating;

1.1: 1,4-dioxane / 3 h / Reflux 1.2: 1 h / Reflux 2.1: 1,1,1,3,3,3-hexamethyl-disilazane / acetonitrile / 0.5 h / 0 °C 2.2: 7 h 2.3: 15.5 h / -18 - 20 °C 3.1: lithium carbonate; lithium bromide / N,N-dimethyl-formamide / 3 h / 120 °C View Scheme

1.1: 1,1,1,3,3,3-hexamethyl-disilazane / acetonitrile / 0.5 h / 0 °C 1.2: 7 h 1.3: 15.5 h / -18 - 20 °C 2.1: lithium carbonate; lithium bromide / N,N-dimethyl-formamide / 3 h / 120 °C View Scheme

1.1: toluene / 5 h / Reflux 2.1: 1,4-dioxane / 3 h / Reflux 2.2: 1 h / Reflux 3.1: 1,1,1,3,3,3-hexamethyl-disilazane / acetonitrile / 0.5 h / 0 °C 3.2: 7 h 3.3: 15.5 h / -18 - 20 °C 4.1: lithium carbonate; lithium bromide / N,N-dimethyl-formamide / 3 h / 120 °C View Scheme

1.1: SiO2; Al2O3; 5A mol. sieves / tetrahydrofuran / 18 h / 20 °C 2.1: hydroquinone / 40 h / 45 °C 2.2: 83 percent / 20 percent aq. AcOH / tetrahydrofuran / 3 h View Scheme

Reaktion ueber mehrere Stufen;