1: Pb(NO3)2, Et3N / CH2Cl2 / 48 h / Ambient temperature 2: 94 percent / DIBAL / toluene / 0.5 h / -78 °C 3: 1) N-chlorosuccinimide, Me2S, 2) NEt3 / 1) toluene, -25 deg C, 5.5 h, 2) 20 min. 4: 91 percent / tetrahydrofuran / 1 h / -40 deg C to r.t. 5: 1) N-chlorosuccinimide, Me2S, 2) NEt3 / 1) toluene, -25 deg C, 5.5 h 2) 20 min 6: HBr, H2O / diethyl ether / 0.5 h / 0 °C 7: NaHCO3, Na2CO3 / H2O / 2.5 h / Ambient temperature 8: 80 percent / pyridine / 20 h / 0 °C 9: pyridine / CH2Cl2 / 0.33 h / -15 °C 10: 1) Bu4NOAc, 2) DMAP, Py / 1) CH3CN, 40 deg C, 50 min, 2) 3 h, r.t. 11: 93 percent / NaBH4 / ethanol 12: 93 percent / K2CO3 / methanol / 1 h / 0 °C 13: 1) methyl triflate, 2) N-methylimidazole / 1) THF, 0 deg C, 40 min, 2) THF 14: 89 percent / H2, NaOAc / 10percent Pd/C / methanol 15: 95 percent / CF3COOH / H2O; dioxane View Scheme

1: aq. Na2CO3 / CH2Cl2 / 0.5 h / Ambient temperature 2: 95 percent / Dowex 50W-X8 resin, water / methanol / 16 h / Ambient temperature; further catalysts and solvents 3: 78 percent / Et3N / CH2Cl2 / 0.17 h / 0 °C 4: 95 percent / H2, sodium acetate / Pd-C / methanol / 10 h 5: 89 percent / Dowex 50W-X8, water / tetrahydrofuran / Heating View Scheme

<b>With</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '3587329', constants.ctx, '0')">tri-n-butyl-tin hydride</a>&nbsp;<b>in</b>&nbsp; <a href="#" onclick="return RXDsubstances(event, this, '635760', constants.ctx, '0')">toluene</a> <br />T=20&deg;C;&nbsp;24&nbsp;h;&nbsp;<br /> &nbsp;