1: ethyl acetate With n-butyllithium; diisopropylamine in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: (E)-2-Methyl-3-phenylpropenoyl chloride in tetrahydrofuran; hexane T=-78°C;

1: With lithium diisopropyl amide in tetrahydrofuran T=-78°C; 2: With manganese(IV) oxide in dichloromethane Further stages.;

1.1: oxalyl chloride; dimethylformamide / CH2Cl2 / 3 h / 0 °C 2.1: n-butyllithium; diisopropylamine / hexane; tetrahydrofuran / 0.5 h / -78 °C 2.2: 69 percent / hexane; tetrahydrofuran / -78 °C View Scheme