titanium tetrachloride in dichloromethane T=0°C; 1 h;

potassium carbonate in acetone 5 h; Heating;

1: 74 percent / BBr3 / CH2Cl2 / 1 h / 0 °C 2: 79.6 percent / K2CO3 / butan-2-one / 4.5 h / Heating 3: 82.9 percent / H2, conc.H2SO4 / 20percent Pd/C / acetic acid / 2 h / 2280 Torr 4: LiCl, Me2SO, H2O / 2 h / Heating 5: H2SO4 / Ambient temperature 6: 69.2 percent / AlCl3 / 1,2-dichloro-ethane / 3.75 h / 5 - 20 °C 7: 20 percent / NH2OH*HCl, pyridine / 4 h / Heating 8: 58 percent / 1 h / 90 °C 9: NaH / dimethylformamide / 4 h / Ambient temperature 10: 92 percent / aq. KOH / methanol / 1 h View Scheme

piperidine in pyridine T=110°C; Knoevenagel condensation; 2 h;

1: (3-carboxypropyl)-triphenylphosphonium bromide With lithium hexamethyldisilazane in tetrahydrofuran T=-50 - -10°C; 2 h; 2: 3-chloro-2,4-dimethoxybenzaldehyde in tetrahydrofuran T=-20 - 20°C; 2.5 h; 3: With citric acid in water pH=3 - 4;