1: 2-bromo-3-methyl-2-butene With lithium in tetrahydrofuran T=20°C; 2 h; 2: (E)-2-Methoxy-3,5-dimethyl-1-morpholin-4-yl-hex-2-en-1-one in tetrahydrofuran T=-78°C; 2 h;

1.1: n-BuLi; dicyclohexylamine / tetrahydrofuran; hexane / 0.5 h / -78 °C 1.2: tetrahydrofuran; hexane / 2 h / -78 °C 2.1: thionyl chloride; triethylamine / CH2Cl2 / 0.5 h / 0 °C 2.2: potassium tert-butoxide / tetrahydrofuran / Heating 3.1: lithium / tetrahydrofuran / 2 h / 20 °C 3.2: 20 percent / tetrahydrofuran / 2 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