1: 94 percent / BF3*THF / tetrahydrofuran / 2.5 h / Ambient temperature 2: 87 percent / HIO3, I2 / ethanol; H2O / 1) 2 h, 2) 60 deg C, 1 h View Scheme

1H-imidazole in N,N-dimethyl-formamide

1.1: 70 percent / NaH / tetrahydrofuran / 16 h / 4 - 22 °C 2.1: iPrMgCl / tetrahydrofuran / 2 h / -20 °C 2.2: tetrahydrofuran / 16 h / -20 - 22 °C 2.3: 82 percent / TFA / CH2Cl2 / 2 h / 22 °C 3.1: 99 percent / LiOH / methanol; H2O / 1 h View Scheme

hydrogenchloride; zinc in acetic acid 2 h; Heating;