1: 40 percent / CrO3 / 100 °C 2: 13 percent Chromat. / tetra-n-butylammonium fluoride / tetrahydrofuran / 2 h / 20 °C View Scheme

1: (i) Cl2, (UV-irradiation), (ii) SbF3, (heating) 2: CrO3, AcOH View Scheme

1: With chlorosulfonic acid T=125°C; 18 h; 2: With ammonium hydroxide in isopropyl alcohol T=-65 - 0°C; 1.5 h;

1.1: chlorosulfonic acid / 18 h / 125 °C 1.2: 1.5 h / -65 - 0 °C 2.1: N-ethyl-N,N-diisopropylamine / N,N-dimethyl-formamide / 1.5 h / 50 °C 3.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 3 h / 18 - 25 °C 3.2: 0 °C 4.1: N-ethyl-N,N-diisopropylamine; HATU / isobutyramide / 1 h / 18 - 25 °C View Scheme

1.1: chlorosulfonic acid / 18 h / 125 °C 1.2: 1.5 h / -65 - 0 °C 2.1: N-ethyl-N,N-diisopropylamine / N,N-dimethyl-formamide / 1.5 h / 50 °C 3.1: water; lithium hydroxide hydrate / tetrahydrofuran; methanol / 3 h / 18 - 25 °C 3.2: 0 °C 4.1: N-ethyl-N,N-diisopropylamine; HATU / isobutyramide / 1 h / 18 - 25 °C 5.1: borane-THF / tetrahydrofuran / 18 - 25 °C 5.2: 3 h 5.3: pH ~ 10 View Scheme

chlorosulfonic acid T=120°C; 18 h;