sodium t-butanolate in methanol T=20°C; 4 h;

sodium methylate in tetrahydrofuran; methanol T=-45°C; 0.5 h; Inert atmosphere;

1.1: 83.5 percent / Et3N / dimethylformamide / 6 h / 20 °C 2.1: 91 percent / Cs2CO3; K2CO3 / dimethylformamide / 10 h / 20 °C 3.1: (Me3Si)2NLi / tetrahydrofuran / 0.33 h / 0 °C 3.2: 90 percent / tetrahydrofuran / 12 h / 20 °C 4.1: 99 percent / sodium tert-butoxide / methanol / 4 h / 20 °C View Scheme

1.1: 91 percent / Cs2CO3; K2CO3 / dimethylformamide / 10 h / 20 °C 2.1: (Me3Si)2NLi / tetrahydrofuran / 0.33 h / 0 °C 2.2: 90 percent / tetrahydrofuran / 12 h / 20 °C 3.1: 99 percent / sodium tert-butoxide / methanol / 4 h / 20 °C View Scheme

1.1: (Me3Si)2NLi / tetrahydrofuran / 0.33 h / 0 °C 1.2: 90 percent / tetrahydrofuran / 12 h / 20 °C 2.1: 99 percent / sodium tert-butoxide / methanol / 4 h / 20 °C View Scheme

1: 2,5-dihydroxy-benzaldehyde With pivaloyl chloride; triethylamine in N,N-dimethyl-formamide T=20°C; 2: 2-iodo-propane With potassium carbonate; caesium carbonate in N,N-dimethyl-formamide T=20°C; 3: triphenyl-methyl-phosphonium iodide Further stages;

1.1: sodium hydride / tetrahydrofuran / 2 h / 60 °C / Inert atmosphere 1.2: 30 °C / Inert atmosphere 2.1: sodium methylate / tetrahydrofuran; methanol / 0.5 h / -45 °C / Inert atmosphere View Scheme

1.1: potassium carbonate / tetrahydrofuran; methanol / 1 h / Inert atmosphere 2.1: potassium carbonate / N,N-dimethyl-formamide / 1 h / 40 °C / Inert atmosphere 2.2: 40 °C / Inert atmosphere 3.1: sodium hydride / tetrahydrofuran / 2 h / 60 °C / Inert atmosphere 3.2: 30 °C / Inert atmosphere 4.1: sodium methylate / tetrahydrofuran; methanol / 0.5 h / -45 °C / Inert atmosphere View Scheme