1.1: lithium diisopropylamide / diethyl ether / -78 °C 1.2: chlorotitanium triisopropoxide / diethyl ether; hexane / -78 °C 1.3: 98 percent / diethyl ether / -78 °C 2.1: 94 percent / LAH / tetrahydrofuran / 1 h / 0 °C 3.1: 81 percent / trifluoroacetic acid / methanol / 4 h / 0 °C View Scheme

1: 94 percent / LAH / tetrahydrofuran / 1 h / 0 °C 2: 81 percent / trifluoroacetic acid / methanol / 4 h / 0 °C View Scheme

1: With ozone in methanol T=-78°C; 2: With dimethylsulfide in methanol T=20°C; 3 h;