1: 3-(3,4-dimethoxyphenyl)-2-propenoic acid With 1,1'-carbonyldiimidazole in tetrahydrofuran T=45°C; 0.25 h; 2: (E)-3-(3,4-dimethoxyphenyl)allyl alcohol With 1,8-diazabicyclo[5.4.0]undec-7-ene in tetrahydrofuran T=45°C; 24 h;

1.1: piperidine; pyridine / 4 h / 118 °C 2.1: 56 percent / LAH / tetrahydrofuran / 4 h / 20 °C 3.1: carbonyldiimidazole / tetrahydrofuran / 0.25 h / 45 °C 3.2: 76 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene / tetrahydrofuran / 24 h / 45 °C View Scheme

1.1: 56 percent / LAH / tetrahydrofuran / 4 h / 20 °C 2.1: carbonyldiimidazole / tetrahydrofuran / 0.25 h / 45 °C 2.2: 76 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene / tetrahydrofuran / 24 h / 45 °C View Scheme