摘要:
Optimized conditions are described for the synthesis of 1-trityl-2-aziridine-carboxylic acid 3 (Trt-Azy-OH) and benzyl (2S)-aziridine-2-carboxylate 6 (H-Azy-OBzl) as useful derivatives for the synthesis of N- and C-terminal aziridine-containing peptides. Thereby, the use of the pentafluorophenyl ester of Trt-Azy-OH was found to be the method of choice in acylating steps, whereas acylation of H-Azy-OBzl several classical methods of peptide synthesis can be successfully used. The fully protected aziridine-2-carboxylic acid peptides are accessible in satisfactory yields as analytically defined products, but partial or total deprotection of these compounds again by standard procedures of peptide synthesis is surprisingly difficult in terms of satisfactory yields, whereby sequence-dependent unstability both in the reaction and purification steps as well as on storage was found to strongly limit the accessibility of these aziridine-containing peptides as promising active-site inactivators of cysteine-proteinases.