1: 1) n-butyllithium / 1) THF, hexane, -78 deg C, 4 min, 2) -78 deg C, 30 min 2: 72 percent / DMSO, oxalyl chloride, NEt3 / 1) CH2Cl2, -78 deg C, 1 h, 2) 0 deg C, 1 h 3: 75 percent / aq. HCl / methanol / 96 h / Ambient temperature View Scheme

Multi-step reaction with 6 steps 1: 1) Li, liquid NH3 / 1) THF, -78 deg C, 45 min, 2) -78 deg C, 30 min2: 1) Hg(OCOCF3)2, 2) aq. HCl / 1) CH3NO2, rt, 42 h, 2) rt, 1 h3: 86 percent / aq. KOH / methanol / 1.5 h / Ambient temperature4: 54 percent / D-camphor-10-sulfonic acid / benzene / 3 h / Heating5: 80 percent / LiAlH4 / tetrahydrofuran / 0.5 h / 0 °C6: 83 percent / DMSO, oxalyl chloride, NEt3 / 1) CH2Cl2, -78 deg C, 1 h, 2) 0 deg C, 1 h