1: 2-methoxy-1-morpholin-4-yl-ethanone With n-butyllithium; N,N-dicyclohexylamine in tetrahydrofuran; hexane T=-78°C; 0.5 h; 2: isobutyl methylketone in tetrahydrofuran; hexane T=-78°C; 2 h;

1.1: thionyl chloride; triethylamine / CH2Cl2 / 0.5 h / 0 °C 1.2: potassium tert-butoxide / tetrahydrofuran / Heating 2.1: tert-butyllithium / tetrahydrofuran / 2 h / -78 °C 2.2: tetrahydrofuran / 4 h / -78 °C View Scheme

1.1: thionyl chloride; triethylamine / CH2Cl2 / 0.5 h / 0 °C 1.2: potassium tert-butoxide / tetrahydrofuran / Heating 2.1: lithium / tetrahydrofuran / 2 h / 20 °C 2.2: 20 percent / tetrahydrofuran / 2 h / -78 °C View Scheme

1: With thionyl chloride; triethylamine in dichloromethane T=0°C; 0.5 h; 2: With potassium tert-butylate in tetrahydrofuran Heating;