2: 88 percent / sodium borohydride / methanol / 0.33 h 3: 1.) sodium methoxide, 2.) aq. 20percent titanium trichloride, aq. ammonium acetate / 1.) methanol, 5 min, 2.) room temperature, 45 min 4: 49 percent / sodium cyanoborohydride, dimethylamine hydrochloride / methanol / 2 h / Ambient temperature View Scheme