1: 49 percent / toluene / 0.5 h / -20 - 20 °C 2: 1.) pTSA, 2.) Dess-Martin's periodinane / 1.) MeOH, CH2Cl2, RT, 2 h, 2.) CH2Cl2, RT, 30 min 4: LiOH / tetrahydrofuran; H2O / 18 h / Ambient temperature 5: Li, liq. NH3 / ethanol / 0.5 h / -78 °C View Scheme