1: 96 percent / hydrogen fluoride, pyridine / acetonitrile / 1 h / Ambient temperature 2: 84 percent / 5N NaOH / methanol / 6 h / 20 - 40 °C View Scheme

Multi-step reaction with 4 steps 1: 79 percent / mesyl chloride, triethylamine / CH2Cl2 / 1 h / 0 °C2: 1) t-butyllithium; 2) copper(I)iodide, tributylphosphine3: 59 percent / NaBH4 / methanol / 0.67 h / 0 °C4: 2) NH4OAc, 25percent aq. TiCl3 / 1) MeOH; 2) H2O, MeOH