hydrogen bromide in 1,4-dioxane T=20°C; 0.833333 h;

hydrogen bromide in 1,4-dioxane T=100°C;

n-butyllithium; sulfuric acid 1) CH2Cl2; 2) CH2Cl2; 3) THF; 4) THF; 5) THF; Yield given. Multistep reaction;

piperazine; potassium tert-butylate; trifluoroacetic acid; Merrifield resin solid phase synthesis; Yield given. Multistep reaction;

1: 88 percent / acetonitrile / 1.) reflux, 90 min, 2.) r.t., 80 h 2: 92 percent / 1 M BH3*THF / CH2Cl2 View Scheme

piperazine; potassium tert-butylate; trifluoroacetic acid; Merrifield resin solid phase synthesis; Yield given. Multistep reaction;

1: 2-methoxy-1,3-butadiene; triphenyl(prop-2-ynyl)phosphonium bromide With zinc(II) iodide; zinc; CoBr2(1,2-bis(diphenylphosphino)ethane) in dichloromethane T=20°C; Diels-Alder reaction; 0.5 h; 2: 3,4,5-trimethoxy-benzaldehyde With potassium tert-butylate in dichloromethane T=20°C; 1 h; 3: With 2,3-dicyano-5,6-dichloro-p-benzoquinone in benzene T=20°C; 1 h; Further stages.;

1: 2-methoxy-1,3-butadiene; triphenyl(prop-2-ynyl)phosphonium bromide With zinc(II) iodide; zinc; CoBr2(1,2-bis(diphenylphosphino)ethane) in dichloromethane T=20°C; Diels-Alder reaction; 0.5 h; 2: 3,4,5-trimethoxy-benzaldehyde With potassium tert-butylate in dichloromethane T=20°C; 1 h; 3: With 2,3-dicyano-5,6-dichloro-p-benzoquinone in benzene T=20°C; 1 h; Further stages.;

1: triethylamine / CHCl3 / 0.33 h / 25 - 31 °C 2: CHCl3 / 25 h / Ambient temperature View Scheme

hydrogen bromide in ethanol 1 h; Heating;