18-crown-6 ether; zinc; palladium on activated charcoal in water T=20°C; Dehalogenation;

potassium carbonate in N,N-dimethyl-formamide T=110°C; 2 h;

1: Br2 / CCl4 2: 1.) EtONa / 1.) EtOH, 10 min, 2.) EtOH, reflux View Scheme

ethanol; sodium ethanolate

1: With n-butyl-magnesium bromide; n-butyllithium in tetrahydrofuran; hexane T=0°C; Metallation; 0.5 h; 2: With titanium tetrachloride in tetrahydrofuran; hexane T=0°C; Oxidation; self-coupling; 0.5 h;