1: potassium carbonate, Pb(OAc)4 / acetonitrile / 0.5 h / 0 °C 2: 60 percent / triethylamine, methanesulfonyl chloride / CH2Cl2 / 0.5 h / Ambient temperature 3: 1.) N-bromosuccinimide (NBS), H2O, 2.) 1,8-diazabicyclo<5.4.0>undec-7-ene / 1.) THF, acetonitrile, 2 h, 2.) reflux, 1 h 4: 1.) triethyloxonium tetrafluoroborate, 2.) sodium cyanoborohydride / 1.) CH2Cl2, RT, 12 h, 2.) methanol, RT, 1 h 5: 1.) LDA, 2.) oxygen / 1.) THF, hexane, from -78 deg C to 0 deg C, 2 h 10 min, 2a.) -78 deg C, 15 min, 2b.) RT, 15 min 6: LiAlH4 / tetrahydrofuran / 1 h / Ambient temperature 7: sodium periodate / methanol; H2O / 0.67 h / Ambient temperature 8: sodium, liquid ammonia / tetrahydrofuran; methanol; H2O / 0.5 h / -78 °C 9: 95 percent / 6 M aq. HCl / 0.5 h / 65 - 70 °C View Scheme