1: 1.) n-buthyllithium in hexane / 1.) THF, -20 deg C, 1 h; 2.) THF, -78 deg C, 1h 2: 177 mg / diisobutylaluminum hydride in hexane / diethyl ether / 1.) -78 deg C, 30 min; 2.) 0 deg C, 2 h 3: 87 percent / N,N'-dicyclohexylcarbodiimide / acetonitrile / 12 h / Ambient temperature View Scheme

1: 1.) n-buthyllithium in hexane / 1.) THF, -20 deg C, 1 h; 2.) THF, -78 deg C, 1h 2: 4.5 mg / diisobutylaluminum hydride in hexane / diethyl ether / 1.) -78 deg C, 30 min; 2.) 0 deg C, 2 h View Scheme