tert.-butyl lithium; N-fluoro-N-(phenylsulfonyl)benzene-sulfonamide in toluene 1.5 h; Ambient temperature; Yields of byproduct given;

hydrogenchloride; acetic acid 0.25 h;

toluene-4-sulfonic acid; 3-hydroxy-2,2-dimethylpropanol in toluene 8 h; Reflux;

1: 93 percent / p-TsOH*H2O / benzene / 2.5 h / 70 °C 2: t-BuLi, NFSi / toluene / 1.5 h / Ambient temperature View Scheme

1: 84 percent / HF (g) 2: 96 percent / sodium borohydride / ethanol / 1.83 h / 55 - 60 °C 3: 93 percent / glacial acetic acid, conc. HCl / 0.25 h View Scheme

1: conc. H2SO4 / benzene / 3 h / Heating 2: 1.) diisobutylaluminum hydride, 2.) conc. HCl / 1.) toluene, hexane, -78 deg C, 1.5 h, 2.) THF, -78 deg C, 5 min 3: 1.) n-BuLi/N-isopropylcyclohexylamine / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, -78 deg C, 2 h 4: bromine, triphenyl phosphite / benzene / 1 h / Ambient temperature 5: sodium borohydride, tri-n-butyltin chloride / ethanol / 1.) room temp., 30 min, 2.) reflux, 45 min 6: KOH / ethanol / 1 h / Heating 7: 84 percent / HF (g) 8: 96 percent / sodium borohydride / ethanol / 1.83 h / 55 - 60 °C 9: 93 percent / glacial acetic acid, conc. HCl / 0.25 h View Scheme

1: KOH / ethanol / 1 h / Heating 2: 84 percent / HF (g) 3: 96 percent / sodium borohydride / ethanol / 1.83 h / 55 - 60 °C 4: 93 percent / glacial acetic acid, conc. HCl / 0.25 h View Scheme

1: 1.) n-BuLi/N-isopropylcyclohexylamine / 1.) THF, hexane, -78 deg C, 15 min, 2.) THF, -78 deg C, 2 h 2: bromine, triphenyl phosphite / benzene / 1 h / Ambient temperature 3: sodium borohydride, tri-n-butyltin chloride / ethanol / 1.) room temp., 30 min, 2.) reflux, 45 min 4: KOH / ethanol / 1 h / Heating 5: 84 percent / HF (g) 6: 96 percent / sodium borohydride / ethanol / 1.83 h / 55 - 60 °C 7: 93 percent / glacial acetic acid, conc. HCl / 0.25 h View Scheme

1: bromine, triphenyl phosphite / benzene / 1 h / Ambient temperature 2: sodium borohydride, tri-n-butyltin chloride / ethanol / 1.) room temp., 30 min, 2.) reflux, 45 min 3: KOH / ethanol / 1 h / Heating 4: 84 percent / HF (g) 5: 96 percent / sodium borohydride / ethanol / 1.83 h / 55 - 60 °C 6: 93 percent / glacial acetic acid, conc. HCl / 0.25 h View Scheme

1: sodium borohydride, tri-n-butyltin chloride / ethanol / 1.) room temp., 30 min, 2.) reflux, 45 min 2: KOH / ethanol / 1 h / Heating 3: 84 percent / HF (g) 4: 96 percent / sodium borohydride / ethanol / 1.83 h / 55 - 60 °C 5: 93 percent / glacial acetic acid, conc. HCl / 0.25 h View Scheme