hydrogen; palladium on activated charcoal in ethanol

1: 85 percent / 1,3-dicyclohexylcarbodiimide; 4-dimethylaminopyridine / CH2Cl2 / 2 h / 20 °C 2: 100 percent / H2 / Pd/C / ethanol / 1 h / 2585.74 Torr View Scheme

sodium hydroxide in acetone 1 h; Ambient temperaturepH: 8-8.5;

1: 90 percent / Et3N / H2O; tetrahydrofuran / 12 h / Ambient temperature 2: 90 percent / CH2Cl2 / 36 h / Heating 3: 98 percent / H2 / 5percent Pd/C / aq. ethanol / 2 h / 3102.9 Torr View Scheme

1: Boc2O; DMAP 2: NaOH / methanol; H2O View Scheme

1: Et3N / dioxane / 0 °C 2: 100 percent / H2 / Pd/C / ethanol View Scheme

1: 4-(N,N-dimethlyamino)pyridine; bis-(2-hydroxyethyl)-sulfide; N-α-t-Boc-L-aspartic acid α-t-butylester; dicyclohexyl-carbodiimide in ethyl acetate T=0 - 20°C; Esterification; 16 h; 2: trifluoroacetic acid; 2-tert-butoxycarbonylamino-succinic acid 1-tert-butyl ester 4-[2-(2-hydroxy-ethylsulfanyl)-ethyl] ester in trifluoroacetic acid T=20°C; saponification; 5 h;

1: With 4-methyl-morpholine; isobutyl chloroformate in ethylene glycol dimethyl ether T=-15°C; 0.166667 h; 2: With sodium tetrahydroborate; water in ethylene glycol dimethyl ether T=-15°C; 0.0833333 h;

1: 1.) ethyl chloroformate, triethylamine; 2.) NaBH4 / 1.) THF, -10 deg C, 1 h; 2.) THF, H2O, 0 deg C, 0.5 h, r.t., 3.5 h 2: 1.24 g / oxalyl chloride, DMSO, Et3N / CH2Cl2 / -78 deg C, 0.5 h, 0 deg C, 2 h 3: 87 percent / NaBH3CN / methanol; tetrahydrofuran / 20 h / 0 °C 4: trimethylsilyl triflate / CH2Cl2 / 0.5 h / 0 °C 5: AcOH / methanol 6: NaBH3CN / tetrahydrofuran; methanol / 19.5 h / 0 °C 7: HCl, anisole / H2O; tetrahydrofuran / 17 h / Ambient temperature View Scheme

1.1: N-methylmorpholine; ClCOOEt / tetrahydrofuran / 0.25 h / -5 °C 1.2: NaBH4 / H2O / 3.5 h / 20 °C 1.3: 92 percent / aq. HCl / 5 °C / pH 2 2.1: 95 percent / polymer-bound-NMe3(1+)*Br(OAc)2-; TEMPO / CH2Cl2 / 16 h / 20 °C 3.1: 15 percent / NaOEt / ethanol / 12 h / 20 °C 4.1: ammonium formate / Pd/C / methanol / 2 h / -10 °C 5.1: 3.3 g / N,N-diisopropylamine / dimethylformamide / 16 h / 20 °C View Scheme