1: NaHCO3 / tetrahydrofuran; hexamethylphosphoric acid triamide / 1 h / Ambient temperature 2: 74 percent / tetra-n-butylammonium fluoride / tetrahydrofuran / Ambient temperature 3: 95 percent / LiOH / 1,2-dimethoxy-ethane; H2O / Ambient temperature View Scheme