potassium hydroxide in methanol; water 5 h; Heating;

1: 48 percent / NaBH4 / trifluoroacetic acid / 1 h 2: 1.) potassium nitrosodisulfonate / 1.) pH 7 buffer, Me2CO, 10 min, 2.) room temperature, overnight 3: 66 percent / boron trifluoride etherate / tetrahydrofuran; CH2Cl2 / 28 h / Ambient temperature 4: 85 percent / KOH / methanol; H2O / 5 h / Heating View Scheme

1: 66 percent / boron trifluoride etherate / tetrahydrofuran; CH2Cl2 / 28 h / Ambient temperature 2: 85 percent / KOH / methanol; H2O / 5 h / Heating View Scheme

1: 1.) potassium nitrosodisulfonate / 1.) pH 7 buffer, Me2CO, 10 min, 2.) room temperature, overnight 2: 66 percent / boron trifluoride etherate / tetrahydrofuran; CH2Cl2 / 28 h / Ambient temperature 3: 85 percent / KOH / methanol; H2O / 5 h / Heating View Scheme