1: 100 percent / KOH / methanol / 12 h / Heating 2: p-toluenesulfonic acid / Ambient temperature 3: t-butylamine-borane complex / CH2Cl2 / 2 h / Ambient temperature 4: 83 percent / pyridine / 24 h / Ambient temperature 5: 76 percent / 65 h / 80 °C 6: 78 percent / conc. aq. HCl / methanol / 40 h / 25 °C 7: KOH / methanol / 1 h / Heating View Scheme

1: 100 percent / KOH / methanol / 12 h / Heating 2: p-toluenesulfonic acid / Ambient temperature 3: t-butylamine-borane complex / CH2Cl2 / 2 h / Ambient temperature 4: 83 percent / pyridine / 24 h / Ambient temperature 5: 76 percent / 65 h / 80 °C 6: 78 percent / conc. aq. HCl / methanol / 40 h / 25 °C 7: KOH / methanol / 1 h / Heating View Scheme

With  potassium dichromate in  water; acetic acid  Ambient temperature;   

Multi-step reaction with 3 steps 1: 1.) Li/NH3 2: 86 percent / 4-dimethylaminopyridine / benzene; pyridine / 0.08 h / Ambient temperature3: 96 percent / K2CrO4 / acetic acid; H2O / Ambient temperature  

Multi-step reaction with 3 steps 1: 100 percent / KOH / methanol / 12 h / Heating2: p-toluenesulfonic acid / Ambient temperature3: 88 percent / pyridine / 24 h / Ambient temperature  

Multi-step reaction with 4 steps 1: 100 percent / KOH / methanol / 12 h / Heating2: p-toluenesulfonic acid / Ambient temperature3: 88 percent / pyridine / 24 h / Ambient temperature4: 95 percent / 65 h / 80 °C