1: i-Pr2NEt / CH2Cl2 / 12 h / Ambient temperature 2: TBAF / tetrahydrofuran / 6 h / 40 °C 3: 2,6-lutidine / tetrahydrofuran / 0.33 h 4: 1.) Pd(PPh3)4, H2O, 2.) AgNO3/SiO2 / 1.) THF, 1.7 h, 2.) CH2Cl2, hexane, 2 h 5: 67 percent / PPTS / ethanol / 16 h / 40 °C View Scheme