1: 40 percent / NaOH / methanol; H2O / 3 h / Ambient temperature 2: 73 percent / H2 / Pd-black / methanol; H2O View Scheme

1: 40 percent / NaOH / methanol; H2O / 3 h / Ambient temperature 2: 39 percent / papaine / H2O / 24 h / 38 °C / ethylenediaminetetraacetic acid, cysteine hydrochloride, pH 4.8 3: 72 percent / FeCl3 / H2O; dioxane / 0.67 h / 35 °C 4: 82 percent / H2 View Scheme

Multi-step reaction with 2 steps 1: 40 percent / NaOH / methanol; H2O / 3 h / Ambient temperature2: 39 percent / papaine / H2O / 24 h / 38 °C / ethylenediaminetetraacetic acid, cysteine hydrochloride, pH 4.8