1: With diisobutylaluminium hydride in dichloromethane T=-35°C; 0.25 h; 2: With diisobutylaluminium hydride in dichloromethane T=0 - 20°C; 4 h; 3: With manganese(IV) oxide; sodium hydroxide more than 3 stages;

sodium hydroxide in tetrahydrofuran; methanol; water T=20°C; 18 h;