1: 1.) NEt3, 2.) H2O / 1.) THF, 0.5 h, room temperature, 2.) CH2Cl2, 0.5 h 2: NEt3 / CHCl3 / 15 h / Ambient temperature 3: 3 M aq. HCl 4: 1.) NaH / 1.) THF, 0.5 h, reflux, 2.) 10 min, reflux 5: 27.6 percent / Bu3SnH, Et3B / toluene; hexane / Heating View Scheme