1: 93 percent / conc. HCl / 16 h / Heating 2: DIBAL-H / toluene / 0.67 h / Heating 4: HOBT, DEC / dimethylformamide / 24 h / 25 °C 5: TFA / CH2Cl2 / 24 h / 25 °C 6: 82 percent / CH2Cl2 / 48 h / 25 °C View Scheme