[NH:1](C(OCC1C=CC=CC=1)=O)[C@H:2]([C:11]([NH:13][C@H:14]([C:22]([OH:24])=[O:23])[CH2:15][C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)=[O:12])[CH2:3][C:4](=[O:10])[O:5][C:6]([CH3:9])([CH3:8])[CH3:7].Cl.[H][H].[CH3:38]O>O1CCOCC1.[Pd]>[NH2:1][C@H:2]([C:11]([NH:13][C@H:14]([C:22]([O:24][CH3:38])=[O:23])[CH2:15][C:16]1[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=1)=[O:12])[CH2:3][C:4](=[O:10])[O:5][C:6]([CH3:7])([CH3:8])[CH3:9]48.6 g of Z-Asp(OtBu)-Phe-OCH 3 in 700 ml of methanol are decarbobenzoxylated in a duck-shaped flask at room temperature after adding 33.5 ml of 3 N hydrogen chloride in dioxane and 5 g of 10% strength palladium catalyst on charcoal. After the hydrogen uptake has ended the mixture is filtered and the filtrate evaporated. 38.7 g of a white foam are obtained. In a thin layer chromatogram on silica gel in chloroform-methanol (9:1) Rf = 0.60; in chloroform-acetone (1:1) Rf = 0.58; Rf102E = 0.42. The product is employed for the subsequent condensation without additional purification.
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