1: 100 percent / hydrogen / 5 percent Pd/C / ethanol / 19 h / 20 °C 2: 87 percent / pyridine / 14.5 h / 0 °C 3: 8 percent / lithium aluminum hydride / diethyl ether / 3 h / 21 °C View Scheme

With  titanium(IV) isopropylate; tert.-butylhydroperoxide; diethyl (2R,3R)-tartrate in  dichloromethane T=-23°C; 24 h;