Reinvestigation of the reactions of carbodiimides with alkoxycarbonylamino acid symmetrical anhydrides
1994; Wiley; Volume: 43; Issue: 2 Linguagem: Inglês
10.1111/j.1399-3011.1994.tb00521.x
ISSN0367-8377
AutoresJan Izdebski, Alicja Orłowska, R. Anulewicz, Ewa Witkowska, D. Fiertek,
Tópico(s)Amino Acid Enzymes and Metabolism
ResumoAlkoxycarbonylamino acid symmetrical anhydrides were allowed to react with N,N′ ‐diisopropylcarbodiimide. The determination of the decrease in carbodiiniide concentration indicated that the reaction was slow and proceeded indirectly. It is presumed that symmetrical anhydride in the presence of basic carbodiimide is converted into oxazolone and alkoxycarbonylamino acid. The latter reacts with carbodiimide to give O ‐acylisourea which, in turn, rearranges to N ‐acylurea. A second minor product was found to be N‐(N 1 ,N 2 ‐bisalkoxycarbonyldipeptidyl)urea. The main pathway leading to the formation of this product starts with rearrangement of the symmetrical anhydride to N 1 , N 2 ‐bisalkoxycarbonyldipeptide acid. These experiments suggest that the reaction between anhydride and carbodiimide is not the source of N ‐acylurea in peptide synthesis.
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