1: 1-diphenylphosphinoyl-4-phenyl-butan-2-one With sodium methylate in tetrahydrofuran T=20°C; 0.25 h; 2: benzyl bromide in tetrahydrofuran T=20°C; 5 h; Further stages.;

1: (E)-3-diphenylphosphinoyl-6-phenyl-hex-5-en-2-one With lithium diisopropyl amide in tetrahydrofuran T=0°C; 0.25 h; 2: 1-[(E)-3-bromo-1-propenyl]benzene in tetrahydrofuran T=-78°C; Further stages.;

1.1: n-BuLi / tetrahydrofuran / 0.25 h / 0 °C 1.2: 69 percent / tetrahydrofuran / 8 h / -78 °C 2.1: NaOMe / tetrahydrofuran / 0.25 h / 20 °C 2.2: 95 percent / tetrahydrofuran / 5 h / 20 °C View Scheme

1.1: NaOMe / tetrahydrofuran / 0.25 h / 20 °C 1.2: 87 percent / tetrahydrofuran / 6 h / 20 °C 2.1: LDA / tetrahydrofuran / 0.25 h / 0 °C 2.2: 52 percent / tetrahydrofuran / -78 °C View Scheme

1.1: n-BuLi / tetrahydrofuran / 0.25 h / 0 °C 1.2: 69 percent / tetrahydrofuran / 8 h / -78 °C 2.1: NaOMe / tetrahydrofuran / 0.25 h / 20 °C 2.2: 95 percent / tetrahydrofuran / 5 h / 20 °C View Scheme