1: 74 percent / 1 M NaOH / dioxane / 3 h / Ambient temperature 2: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 7 3: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C 4: 1.) Na/NH3, 2.) NH4Cl, 3.) trifluoroacetic acid, O2 View Scheme

Multi-step reaction with 2 steps 1: 74 percent / 1 M NaOH / dioxane / 3 h / Ambient temperature2: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 7  

Multi-step reaction with 3 steps 1: 74 percent / 1 M NaOH / dioxane / 3 h / Ambient temperature2: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 73: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C  

With  sodium hydroxide in  1,4-dioxane 3 h;  Ambient temperature;