1: With pyridine; thionyl chloride T=0°C; 0.166667 h; 2: With lithium hexamethyldisilazane in tetrahydrofuran; hexane T=-70°C; 2 h; 3: With 2,2'-azo-bisisobutyronitrile; tri-n-butyl-tin hydride in toluene 0.166667 h; Heating;

1: SeO2, pyridine / 2-methyl-propan-2-ol / 31 h / Heating 2: KOH / methanol; H2O / 90 h / Heating View Scheme

1.1: 92 percent / NaOMe / benzene / 3 h / 0 °C 2.1: 80 percent / aq. HCl / ethanol / 18 h / Heating 3.1: LDA / tetrahydrofuran; hexane / 0.5 h / -70 °C 3.2: 93 percent / tetrahydrofuran; hexane / 2 h / -70 °C 4.1: SOCl2; pyridine / 0.17 h / 0 °C 4.2: lithium bis(trimethylsilyl)amide / tetrahydrofuran; hexane / 2 h / -70 °C 4.3: 0.19 g / tributyltinhydride; azobisisobutylnitrile / toluene / 0.17 h / Heating View Scheme

(i) aq. N2H4, KOH, ethane-1,2-diol, (ii) aq. HI, AcOH; Multistep reaction;

1.1: LDA / tetrahydrofuran; hexane / 0.5 h / -70 °C 1.2: 93 percent / tetrahydrofuran; hexane / 2 h / -70 °C 2.1: SOCl2; pyridine / 0.17 h / 0 °C 2.2: lithium bis(trimethylsilyl)amide / tetrahydrofuran; hexane / 2 h / -70 °C 2.3: 0.19 g / tributyltinhydride; azobisisobutylnitrile / toluene / 0.17 h / Heating View Scheme

1.1: 80 percent / aq. HCl / ethanol / 18 h / Heating 2.1: LDA / tetrahydrofuran; hexane / 0.5 h / -70 °C 2.2: 93 percent / tetrahydrofuran; hexane / 2 h / -70 °C 3.1: SOCl2; pyridine / 0.17 h / 0 °C 3.2: lithium bis(trimethylsilyl)amide / tetrahydrofuran; hexane / 2 h / -70 °C 3.3: 0.19 g / tributyltinhydride; azobisisobutylnitrile / toluene / 0.17 h / Heating View Scheme

1.1: 5.1 g / H2SO4 / 20 h / Heating 2.1: LDA / tetrahydrofuran; hexane / 0.5 h / -70 °C 2.2: 73 percent / tetrahydrofuran; hexane / 2 h / -70 °C 3.1: SOCl2; pyridine / 0.17 h / 0 °C 3.2: t-BuOK / o-xylene / 0.08 h / 160 °C 3.3: 7 percent / MgCl2*6H2O / dimethylsulfoxide / 3 h / 160 °C View Scheme

1.1: LDA / tetrahydrofuran; hexane / 0.5 h / -70 °C 1.2: 73 percent / tetrahydrofuran; hexane / 2 h / -70 °C 2.1: SOCl2; pyridine / 0.17 h / 0 °C 2.2: t-BuOK / o-xylene / 0.08 h / 160 °C 2.3: 7 percent / MgCl2*6H2O / dimethylsulfoxide / 3 h / 160 °C View Scheme

1.1: aq. HCl / 18 h / Heating 2.1: 5.1 g / H2SO4 / 20 h / Heating 3.1: LDA / tetrahydrofuran; hexane / 0.5 h / -70 °C 3.2: 73 percent / tetrahydrofuran; hexane / 2 h / -70 °C 4.1: SOCl2; pyridine / 0.17 h / 0 °C 4.2: t-BuOK / o-xylene / 0.08 h / 160 °C 4.3: 7 percent / MgCl2*6H2O / dimethylsulfoxide / 3 h / 160 °C View Scheme