1: 89 percent / SiO2, 0.5 N HCl / CHCl3 / 2 h / 40 °C / sonication 2: 76 percent / LiOH, LiBr, n-Bu4NBr / acetonitrile / 8 h / Ambient temperature 3: 86 percent / NaHCO3 / ethanol / sonication View Scheme

1: 89 percent / 0.5 N aq. HCl, silica gel / CHCl3 / 2 h / 40 °C 2: LiBr, tetrabutylammonium bromide, LiOH*H2O / acetonitrile / 8 h / Ambient temperature View Scheme