1: Zn, conc. aq.NH4OH, CuSO4 / 24 h / Heating 2: 1) ZnCl2, 2) CrO3 / 1) acetic acid, reflux, 3 h, 2) acetic acid, 0.5 h 3: 90 percent / NaBH4 / methanol / 2 h View Scheme

1: 1) ZnCl2, 2) CrO3 / 1) acetic acid, reflux, 3 h, 2) acetic acid, 0.5 h 2: 90 percent / NaBH4 / methanol / 2 h View Scheme

1.1: copper(I) oxide; potassium carbonate / pyridine / 2 h / 20 °C / |Inert atmosphere 1.2: 17 h / 20 °C / |Inert atmosphere 2.1: water / N,N-dimethyl-formamide; methanol / 20 h / |Inert atmosphere; |Reflux View Scheme

1.1: toluene; tetrahydrofuran / 12 h / 0 °C / |Inert atmosphere 2.1: N-bromosuccinmide / N,N-dimethyl-formamide / 0.5 h / 20 °C / |Inert atmosphere 3.1: copper(I) oxide; potassium carbonate / pyridine / 2 h / 20 °C / |Inert atmosphere 3.2: 17 h / 20 °C / |Inert atmosphere 4.1: water / N,N-dimethyl-formamide; methanol / 20 h / |Inert atmosphere; |Reflux View Scheme

1.1: N-bromosuccinmide / N,N-dimethyl-formamide / 0.5 h / 20 °C / |Inert atmosphere 2.1: copper(I) oxide; potassium carbonate / pyridine / 2 h / 20 °C / |Inert atmosphere 2.2: 17 h / 20 °C / |Inert atmosphere 3.1: water / N,N-dimethyl-formamide; methanol / 20 h / |Inert atmosphere; |Reflux View Scheme

pyridinium chlorochromate