1: With lithium hydroxide hydrate in tetrahydrofuran; methanol; water T=20°C; 2: With hydrogenchloride in water; ethyl acetate T=0°C; pH=4; 1 h;

1: 2,2-dibromo-1-(3',4'-dimethoxyphenyl)ethene With n-butyllithium in hexane T=-78 - 0°C; 1.5 h; 2: methyl chloroformate in hexane T=-78 - 0°C; 1.16667 h;

1.1: triphenylphosphine / CH2Cl2 / 0.5 h / 0 °C 1.2: 88 percent / CH2Cl2 / 1 h / 0 °C 2.1: n-BuLi / hexane / 1.5 h / -78 - 0 °C 2.2: 93 percent / hexane / 1.17 h / -78 - 0 °C View Scheme

1: 1.) AlCl3, 3.) NaHCO3 2: 1 N aq. HCl / CH2Cl2 View Scheme

1: carbon tetrabromide; 3,4-dimethoxy-benzaldehyde With triphenylphosphine in dichloromethane T=0 - 20°C; Corey-Fuchs method; 3 h; Inert atmosphere; 2: With n-butyllithium in tetrahydrofuran; hexane T=-78 - 20°C; Corey-Fuchs method; 1 h; Inert atmosphere; 3: methyl chloroformate in tetrahydrofuran; hexane T=-78 - 20°C; Corey-Fuchs method; 1 h; Inert atmosphere;

sodium hydroxide

bis-triphenylphosphine-palladium(II) chloride; tetrabutylammomium bromide; sodium acetate in N,N-dimethyl-formamide T=100 - 120°C; Larock reaction; 0.5 h; Inert atmosphere;