lithium diisopropyl amide in tetrahydrofuran T=-78°C; 3 h;

chromium(VI) oxide; sulfuric acid; water in acetone 0.166667 h;

1: 1.) disiamylborane; 2.) acetic acid / 1.) THF, 0 deg C-1 h, 20 deg C-4 h; 2.) 0 deg C-8 h 2: 80 percent / Li-diisopropylamide / tetrahydrofuran / 3 h / -78 °C View Scheme