sodium tetrahydroborate in methanol T=0 - 20°C;

1.1: n-butyllithium; DMF / diethyl ether; hexane / 0.42 h / 0 °C 1.2: 81 percent / hexane / 0.17 h / Heating 2.1: 100 percent / sodium borohydride / methanol / 0 - 20 °C View Scheme

diisobutylaluminium hydride in tetrahydrofuran T=20°C; 1 h;