Izdebski J, Orłowska A, Anulewicz R, Witkowska E, Fiertek D
Laboratory of Peptides, University of Warsaw, Poland.
Int J Pept Protein Res. 1994 Feb;43(2):184-9. doi: 10.1111/j.1399-3011.1994.tb00521.x.
Alkoxycarbonylamino acid symmetrical anhydrides were allowed to react with N,N'-diisopropylcarbodiimide. The determination of the decrease in carbodiimide 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-(N1,N2-bisalkoxycarbonyldipeptidyl)urea. The main pathway leading to the formation of this product starts with rearrangement of the symmetrical anhydride to N1,N2-bisalkoxycarbonyldipeptide acid. These experiments suggest that the reaction between anhydride and carbodiimide is not the source of N-acylurea in peptide synthesis.
使烷氧羰基氨基酸对称酸酐与N，N'-二异丙基碳二亚胺反应。对碳二亚胺浓度降低的测定表明该反应缓慢且间接进行。据推测，在碱性碳二亚胺存在下，对称酸酐会转化为恶唑酮和烷氧羰基氨基酸。后者与碳二亚胺反应生成O-酰基异脲，O-酰基异脲继而重排为N-酰基脲。发现第二种次要产物是N-（N1，N2-双烷氧羰基二肽基）脲。形成该产物的主要途径始于对称酸酐重排为N1，N2-双烷氧羰基二肽酸。这些实验表明，酸酐与碳二亚胺之间的反应不是肽合成中N-酰基脲的来源。
