1: 96.5 percent / acetyl chloride / 5 h / 40 °C 2: 2.) H2O / 1.) THF, ether, 10 min; 2.) THF, ether, 12 h 3: 1.) 1 M LiEt3BH; 2.) 3 M NaOH, 30 percent H2O2 / 1.) THF, 0 deg C, 30 h; 2.) 30 h, RT, water 4: 28 percent / PBr3 / diethyl ether / 12 h / 40 °C 5: vitamin B12s / H2O / 0.25 h View Scheme

T=184 - 190°C;

1: 96.5 percent / acetyl chloride / 5 h / 40 °C 2: 2.) H2O / 1.) THF, ether, 10 min; 2.) THF, ether, 12 h 3: 1.) 1 M LiEt3BH; 2.) 3 M NaOH, 30 percent H2O2 / 1.) THF, 0 deg C, 30 h; 2.) 30 h, RT, water 4: 28 percent / PBr3 / diethyl ether / 12 h / 40 °C 5: 100 percent / diethyl ether / 0.17 h 6: 40 percent / vitamin B12s / 0.5 h View Scheme