1: 75 percent / N-bromosuccinimide, H2O / tetrahydrofuran / 3 h / 0 - 25 °C 2: 93 percent / K2CO3 / methanol; diethyl ether / 2 h / 25 °C 3: 88 percent / 37percent HClO4 / tetrahydrofuran; H2O / 2 h / 25 °C 4: 74 percent / NaIO4, conc. H2SO4 / tetrahydrofuran; H2O / 0.5 h / 25 °C 5: 51 percent / tetrahydrofuran; hexane / 0.5 h / -45 °C 6: 1.) Li, EtNH2, 2.) air / 1.) THF, 2.) 25 deg C, 40 min View Scheme