L-Alanine → HCID 131714115, compound

Participants

Reaction Steps

Synthesis: The synthesis of the peptide, Boc-Val-L. Pro-D. Ala-L. Val-Gly-OBzl (I), was carried out using classical solution methods starting from the C-terminal glycine benzyl ester p-tosylate. Each amino acid was coupled to the growing peptide chain by means of the water soluble carbodiimide 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI) and 1-hydroxybenzotriazole. The tert-butyloxycarbonyl group was used for amino group protection, and its removal was achieved with trifluoroacetic acid. Peptide I was converted to the free acid by hydrogenolysis and then to the corresponding p-nitrophenyl ester using p-nitrophenyl trifluoroacetate. After deblocking the Nα -protecting group and neutralizing, H-L. Val-L. Pro-D. Ala-L. Val-Gly-ONp was polymerized in dimethyl sulfoxide for 14 days. The reaction mixture was diluted with water, dialyzed against water and lyophilized. Purity of all intermediate peptides was checked by thin layer chromatography and C-13 NMR spectra. The overall yields were 80-90% in the preparation of the intermediate products and 50% during the polymerization step.

Provenance & Evidence