potassium carbonate in N,N-dimethyl-formamide 1 h;

1: 90 percent / Heating 2: 1.) BuLi / 1.) ether, hexane, -80 deg C, 15 min, 2.) ether, hexane, from -80 deg C to RT 3: aq. HCl / 2 h / 100 °C 4: 1.) BuLi / 1.) THF, hexane, from 0 deg C to RT, 2.) THF, hexane, reflux, 1 h 5: 1.) BH3*S(CH3)2, 2-methyl-2-butene, 2.) I2, NaOH / 1.) THF, RT, 2.) THF, MeOH 6: dimethylformamide / 1.5 h / Heating 7: 66percent aq. hydrazine / butan-1-ol / 2 h / 100 °C View Scheme

1: 90 percent / Heating 2: 1.) BuLi / 1.) ether, hexane, -80 deg C, 15 min, 2.) ether, hexane, from -80 deg C to RT 3: aq. HCl / 2 h / 100 °C 4: 1.) BuLi / 1.) THF, hexane, from 0 deg C to RT, 2.) THF, hexane, reflux, 1 h 5: 1.) BH3*S(CH3)2, 2-methyl-2-butene, 2.) I2, NaOH / 1.) THF, RT, 2.) THF, MeOH 6: 66percent aq. hydrazine / butan-1-ol / 2 h / 100 °C View Scheme