1: With iodine in acetic acid T=20°C; 2: With isoascorbic acid in acetic acid

1: N-(9-fluorenylmethoxycarbonyl)glycine With ethyl (hydroxylimino)cyanoacetate; diisopropyl-carbodiimide in N,N-dimethyl-formamide T=20°C; 1 h; 2: With piperidine in N,N-dimethyl-formamide 3: N-Fmoc-L-leucine; C27H27NO7S2; Fmoc–Pro–OH; fmoc-L-Ile-OH; fmoc-O-tert-butyl-L-tyrosine; fmoc-Asn(trt)-OH; fmoc-Gln(Trt)-OH Further stages;

1.1: sodium dihydrogenphosphate; tris-(2-carboxyethyl)-phosphine hydrochloride / pH 7.2 / Inert atmosphere 1.2: Inert atmosphere 2.1: ammonium hydroxide; acetic acid / water / 6 h / pH 7 View Scheme

1.1: trifluoroacetic acid / chloroform / 1 h / Inert atmosphere 2.1: tert-butylisonitrile; benzotriazol-1-ol / chloroform / 20 °C / Inert atmosphere 3.1: trifluoroacetic acid / chloroform / 1 h / Inert atmosphere 4.1: tert-butylisonitrile; benzotriazol-1-ol / chloroform / 20 °C / Inert atmosphere 5.1: ammonia / methanol / 24 h / Inert atmosphere 6.1: tri-iso-propylsilane; water; trifluoroacetic acid; phenol / 1.5 h / 20 °C / Inert atmosphere 7.1: sodium dihydrogenphosphate; tris-(2-carboxyethyl)-phosphine hydrochloride / pH 7.2 / Inert atmosphere 7.2: Inert atmosphere 8.1: ammonium hydroxide; acetic acid / water / 6 h / pH 7 View Scheme

1.1: tert-butylisonitrile; benzotriazol-1-ol / chloroform / 20 °C / Inert atmosphere 2.1: trifluoroacetic acid / chloroform / 1 h / Inert atmosphere 3.1: tert-butylisonitrile; benzotriazol-1-ol / chloroform / 20 °C / Inert atmosphere 4.1: ammonia / methanol / 24 h / Inert atmosphere 5.1: tri-iso-propylsilane; water; trifluoroacetic acid; phenol / 1.5 h / 20 °C / Inert atmosphere 6.1: sodium dihydrogenphosphate; tris-(2-carboxyethyl)-phosphine hydrochloride / pH 7.2 / Inert atmosphere 6.2: Inert atmosphere 7.1: ammonium hydroxide; acetic acid / water / 6 h / pH 7 View Scheme

1.1: trifluoroacetic acid / chloroform / 1 h / Inert atmosphere 2.1: tert-butylisonitrile; benzotriazol-1-ol / chloroform / 20 °C / Inert atmosphere 3.1: ammonia / methanol / 24 h / Inert atmosphere 4.1: tri-iso-propylsilane; water; trifluoroacetic acid; phenol / 1.5 h / 20 °C / Inert atmosphere 5.1: sodium dihydrogenphosphate; tris-(2-carboxyethyl)-phosphine hydrochloride / pH 7.2 / Inert atmosphere 5.2: Inert atmosphere 6.1: ammonium hydroxide; acetic acid / water / 6 h / pH 7 View Scheme

solid phase synthesis; the next amino acids are: Fmoc-Asn-OH, Fmoc-Gln-OH, Fmoc-Ile-OH and Fmoc-Tyr(tBu)-OH; Yield given. Multistep reaction;

in water T=25°C; 5 h; pH 7.0; Equilibrium constant;

in water T=25°C; 5 h; pH 7.0; Rate constantEquilibrium constant;

in water T=25°C; 5 h; pH 7.0; Rate constantEquilibrium constant;