Schwartz's reagent in tetrahydrofuran T=20°C; 0.5 h;

1: 1.) LDA / 1.) THF, hexane, -78 deg C, 0.5 h, 2.) from -25 deg C to 0 deg C 4 h 2: 75 percent / LiOBn / tetrahydrofuran; hexane / 1.5 h / 0 °C View Scheme