1: sodium amide / 18-crown-6-ether / 1.) xylene, reflux, 40 min. 2.) xylene, reflux, 8 h 2: p-toluenesulphonic acid / methanol / 1 h / Heating 3: 90 percent / hydrogen / PtO2 / ethanol / 2 h / Heating View Scheme

1: 1.) LiNH2 / 1.) THF, 1.5 h, 2.) 4 h 2: Dowex W-50 (H+ form) / methanol / 20 h 3: H2, 1,2-diaminoethane / P2-Ni / ethanol 4: 85 percent / PPh3, CBr4 / CH2Cl2 / 1.) from 0 deg C to 20 deg C, 1 h, 2) 20 deg C, 14 h 5: 1.) butyllithium, HMPA, 2.) HMPA / 1.) THF, hexane, -20 deg C, 1 h, 2.) RT, 4 h 6: Dowex W-50 (H+ form) / methanol / 16 h 7: 83 percent / lithium alanate / tetrahydrofuran / 10 h / 60 °C View Scheme

toluene-4-sulfonic acid in diethyl ether T=0°C; 2 h;

1: sodium amide / 18-crown-6-ether / 1.) xylene, reflux, 40 min. 2.) xylene, reflux, 8 h 2: p-toluenesulphonic acid / methanol / 1 h / Heating View Scheme

1: sodium amide / 18-crown-6-ether / 1.) xylene, reflux, 40 min. 2.) xylene, reflux, 8 h 2: p-toluenesulphonic acid / methanol / 1 h / Heating 3: lithium aluminium hydride / tetrahydrofuran; bis-(2-methoxy-ethyl) ether / 10 h / Heating View Scheme

1: 1.) LiNH2 / 1.) THF, 1.5 h, 2.) 4 h 2: Dowex W-50 (H+ form) / methanol / 20 h 3: H2, 1,2-diaminoethane / P2-Ni / ethanol 4: 85 percent / PPh3, CBr4 / CH2Cl2 / 1.) from 0 deg C to 20 deg C, 1 h, 2) 20 deg C, 14 h View Scheme