1: 68 percent / pyridine / 16 h / -30 deg C --> 25 deg C 2: 82 percent / DMAP / acetonitrile / 16 h / 25 °C 3: 92 percent / Bu3SnH, AIBN / toluene / 5 h / 120 °C 4: 88 percent / AcOH, H2SO4 / CHCl3 / 16 h / 4 °C 5: 46 percent / HMDS, TMS-Cl, CF3SO3H / acetonitrile / 5 h / 80 °C 6: 83 percent / DBU / tetrahydrofuran / 55 h / 60 °C 7: 83 percent / DMAP / acetonitrile / 16 h / 25 °C 8: 89 percent / Bu3SnH, AIBN / toluene / 5 h / 120 °C 9: 50 percent / LiN3, BzOH / dimethylformamide / 20 h / 120 °C 10: 82 percent / NaOCH3 / methanol / 16 h View Scheme

1: 93 percent 2: AcOH, conc. H2SO4 / CH2Cl2 / 16 h / 4 °C 3: 68.5 percent / hexamethyldisilazane, chlorotrimethylsilane, trifluoromethanesulfonic acid / acetonitrile / 12 h / Heating 4: 63 percent / 1,8-diazabicyclo<5.4.0>undec-7-ene (DBU) / toluene / 1.5 h / 90 °C 5: (dimethylamino)pyridine / acetonitrile 6: 85 percent / tributyltin hydride, AIBN / toluene / 120 °C 7: 1.) LiN3, benzoic acid, 2.) 0.1 M NaOCH3 / 1.) DMF, 120 deg C, 12 h, 2.) MeOH View Scheme