1.1: s-BuLi; TMEDA / tetrahydrofuran; cyclohexane / 1 h / -78 °C 1.2: tetrahydrofuran; cyclohexane / -78 - 20 °C 1.3: 99 percent / aq. HCl; NH4Cl / tetrahydrofuran; cyclohexane / pH 5 - 6 2.1: 83 percent / Pd(PPh3)4P; aq. Na2CO3 / 1,2-dimethoxy-ethane / Heating 3.1: 88 percent / LDA / tetrahydrofuran / 6 h / 20 °C 4.1: LDA / tetrahydrofuran; hexane / 0.08 h / 0 °C 4.2: 65 percent / tetrahydrofuran; hexane / 0 - 20 °C 5.1: 73 percent / aq. HCO2H; Pd(OAc)2; Ph3P / dimethylformamide / 60 - 70 °C View Scheme

1.1: 83 percent / Pd(PPh3)4P; aq. Na2CO3 / 1,2-dimethoxy-ethane / Heating 2.1: 88 percent / LDA / tetrahydrofuran / 6 h / 20 °C 3.1: LDA / tetrahydrofuran; hexane / 0.08 h / 0 °C 3.2: 65 percent / tetrahydrofuran; hexane / 0 - 20 °C 4.1: 73 percent / aq. HCO2H; Pd(OAc)2; Ph3P / dimethylformamide / 60 - 70 °C View Scheme

1.1: LDA / tetrahydrofuran; hexane / 0.08 h / 0 °C 1.2: 65 percent / tetrahydrofuran; hexane / 0 - 20 °C 2.1: 73 percent / aq. HCO2H; Pd(OAc)2; Ph3P / dimethylformamide / 60 - 70 °C View Scheme

1.1: 88 percent / LDA / tetrahydrofuran / 6 h / 20 °C 2.1: LDA / tetrahydrofuran; hexane / 0.08 h / 0 °C 2.2: 65 percent / tetrahydrofuran; hexane / 0 - 20 °C 3.1: 73 percent / aq. HCO2H; Pd(OAc)2; Ph3P / dimethylformamide / 60 - 70 °C View Scheme

in acetonitrile UV-irradiation; Title compound not separated from byproducts;

in acetonitrile UV-irradiation; Title compound not separated from byproducts;

Ph3C+ClO4-; acetic acid

T=25°C; 0.0333333 h; UV-irradiation; Title compound not separated from byproducts;

T=100°C;

T=310°C;