1: 54 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 1 h / Ambient temperature; pH 10 2: 62 percent / ferric chloride / dioxane; H2O / 0.5 h / 35 °C 3: 64 percent / α-chymotrypsin / dimethylformamide; various solvent(s) / 20 h / 38 °C / pH 7 4: 59 percent / ferric chloride / dimethylformamide; H2O / 0.5 h / 35 °C 5: 1.) Na/NH3, 2.) NH4Cl, 3.) trifluoroacetic acid, O2 View Scheme

ethanol; hydrazine hydrate N-<S-benzyl-N-benzyloxycarbonyl-L-cysteinyl>-L-tyrosine hydrazide;

triethylamine; α-chymotrypsin in water; isopropyl alcohol T=30°C; 18 h; 5percent of water; Product distribution;

triethylamine; α-chymotrypsin in water; isopropyl alcohol T=30°C; 25 h; 2percent of water; other content of water, other time; Product distribution;

triethylamine; α-chymotrypsin in water; isopropyl alcohol T=30°C; 48 h; 2percent of water; other content of water, other time; Product distribution;