lithium aluminium tetrahydride in tetrahydrofuran T=20°C; 19 h; Heating / reflux;

1: With dimethyl sulfoxide; trifluoroacetic anhydride in dichloromethane T=-78°C; 0.5 h; 2: (rac)-1-Benzyl-3,3-dimethyl-piperidin-4-ol in dichloromethane T=-78°C; 1 h; 3: With triethylamine in dichloromethane T=0°C; 2 h;