1: 83 percent / KHMDS / tetrahydrofuran / 18 h / -78 - 25 °C 2: 97 percent / LiOH / methanol; H2O / 1 h / 25 °C 3: 94.2 percent / EDCI; DMAP / CH2Cl2 / 16 h / 25 °C 4: 99 percent / TFA / CH2Cl2 / 2 h / 25 °C 5: 83 percent / propan-2-ol / 16 h / 80 °C 6: 73 percent / TFA / tetrahydrofuran; H2O / 0.33 h / 0 °C View Scheme