1: 83 percent / L-Selectride / tetrahydrofuran / -78 deg C, 2 h, to room temp., 4 h 2: 39.1 percent / cuprous bromide, diisopropylamine / dioxane / 21 h / Heating 3: 57 percent / barium manganate / CH2Cl2 / 37 h / Ambient temperature View Scheme

Multi-step reaction with 2 steps 1: 83 percent / L-Selectride / tetrahydrofuran / -78 deg C, 2 h, to room temp., 4 h2: 39.1 percent / cuprous bromide, diisopropylamine / dioxane / 21 h / Heating