1: With copper(I) bromide dimethylsulfide complex; (+)-(R,Rp)-taniaphos in dichloromethane; toluene T=-80°C; 4 h; Schlenk techniqueInert atmosphere; 2: With ozone in dichloromethane; toluene T=-80°C; 0.333333 h; Inert atmosphereSchlenk technique; 3: With sodium tetrahydroborate in dichloromethane; water; toluene T=-80 - 20°C; Inert atmosphereSchlenk technique; Overall yield = 84 percent; Overall yield = 27 mg; enantioselective reaction;