1: n-BuLi / tetrahydrofuran; hexane / 0.17 h / 0 °C 2: 2.) TBAF / 1.) pyridine, 0 deg C, 30 min, RT, 1 h; 2.) pyridine, THF, RT, 7 h 3: K2CO3 / dimethylformamide / 6 h / Ambient temperature 4: 90 percent Spectr. / Pd(OAc)2, bis(2-(diphenylphosphino)phenyl) ether, 4 Angstroem molecular sieves, Et3N, Cs2CO3 / toluene / 18 h / 110 °C 5: aq. HCl / tetrahydrofuran; ethanol / 1 h 6: NH4HCO2 / 20 percent Pd(OH)2/C / tetrahydrofuran; propan-2-ol / 1 h / Heating View Scheme

(R)-1-phenyl-ethyl-amine in isopropyl alcohol 20 h; Ambient temperature;

Fmoc-L-Asn(Trt)-L-Asn(Trt)-NH(CH2)6CONH(CH2)3-silica gel in chloroform

1: pyridine / dichloromethane / 24 h / 20 °C 2: C88H48F24N(1+)*Br(1-); potassium hydroxide / toluene; water / 48 h / 0 °C 3: magnesium; titanium (IV) isopropoxide; chloro-trimethyl-silane / tetrahydrofuran / 20 h / 50 °C / |Inert atmosphere 4: boron tribromide / dichloromethane / 3 h / 0 °C / |Inert atmosphere View Scheme

benzylamine; copper dichloride in methanol 48 h; Ambient temperature; Yields of byproduct given;

1: pyridine / dichloromethane / 24 h / 20 °C 2: C88H48F24N(1+)*Br(1-); potassium hydroxide / toluene; water / 48 h / 0 °C 3: [1,3-bis(diphenylphosphino) propane] dichloronickel(II); diisobutylaluminium hydride / toluene / 3 h / 0 - 20 °C 4: magnesium; titanium (IV) isopropoxide; chloro-trimethyl-silane / tetrahydrofuran / 20 h / 50 °C / |Inert atmosphere View Scheme