1: 96 percent / imidazole; DMAP / CH2Cl2 / 6 h / 0 - 20 °C 2: 92 percent / Na; NH3 / tetrahydrofuran / 0.08 h / -33 °C 3: 65 percent / PCC / benzene / 6 h / Heating 4: TEA / 12 h / 20 °C 5: DIPEA; DMAP / CH2Cl2 / 2 h / 0 - 20 °C 6: 98 percent / TBAF / tetrahydrofuran / 6 h / 0 - 20 °C 7: 75 percent / LDA / tetrahydrofuran / 3 h / -78 - -20 °C 8: 88 percent / LiOH / tetrahydrofuran; H2O / 12 h / 20 °C 9: 76 percent / PhSO2Cl; pyridine / tetrahydrofuran / 12 h / 0 °C 10: 88 percent / BF3*OEt2; ethane dithiol / CH2Cl2 / 1 h / 0 - 20 °C View Scheme

1: 96 percent / imidazole; DMAP / CH2Cl2 / 6 h / 0 - 20 °C 2: 92 percent / Na; NH3 / tetrahydrofuran / 0.08 h / -33 °C 3: 65 percent / PCC / benzene / 6 h / Heating 4: TEA / 12 h / 20 °C 5: DIPEA; DMAP / CH2Cl2 / 2 h / 0 - 20 °C 6: 98 percent / TBAF / tetrahydrofuran / 6 h / 0 - 20 °C 7: 75 percent / LDA / tetrahydrofuran / 3 h / -78 - -20 °C 8: 88 percent / LiOH / tetrahydrofuran; H2O / 12 h / 20 °C 9: 76 percent / PhSO2Cl; pyridine / tetrahydrofuran / 12 h / 0 °C 10: 88 percent / BF3*OEt2; ethane dithiol / CH2Cl2 / 1 h / 0 - 20 °C 11: 90 percent / DIAD; TPP / tetrahydrofuran / 3 h / 0 - 20 °C View Scheme

1: 96 percent / imidazole; DMAP / CH2Cl2 / 6 h / 0 - 20 °C 2: 92 percent / Na; NH3 / tetrahydrofuran / 0.08 h / -33 °C 3: 65 percent / PCC / benzene / 6 h / Heating 4: TEA / 12 h / 20 °C 5: DIPEA; DMAP / CH2Cl2 / 2 h / 0 - 20 °C 6: 98 percent / TBAF / tetrahydrofuran / 6 h / 0 - 20 °C 7: 75 percent / LDA / tetrahydrofuran / 3 h / -78 - -20 °C 8: 88 percent / LiOH / tetrahydrofuran; H2O / 12 h / 20 °C 9: 76 percent / PhSO2Cl; pyridine / tetrahydrofuran / 12 h / 0 °C 10: 88 percent / BF3*OEt2; ethane dithiol / CH2Cl2 / 1 h / 0 - 20 °C View Scheme