Formation of optically pure N-acyl-N,N'-dicyclohexylurea in N,N'-dicyclohexylcarbodiimide-mediated peptide synthesis.
N-acylurea, a side product in peptide synthesis from DCC, preserves its chiral integrity although peptides formed simultaneously in the same reaction are racemized to a large extent. This observation is inconsistent with the generally accepted opinion that racemization-prone O-acylisourea is a common intermediate for both peptides and N-acylurea. Chiral purity of N-acylureas and peptides was determined by HPLC using chiral stationary phases. An efficient method of synthesis of chirally pure N-acylureas is also presented.
Department of Organic Chemistry, Technical University of Gdańsk, Poland.
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M
Slebioda
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Z
Wodecki
A M
AM
Kołodziejczyk
D000596:Amino Acids; D002234:Carbodiimides; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D003512:Cyclohexanones; D004024:Dicyclohexylcarbodiimide; D004151:Dipeptides; D007202:Indicators and Reagents; D010455:Peptides / Q000138:chemical synthesis*; D013237:Stereoisomerism; D014508:Urea / Q000031:analogs & derivatives* / Q000138:chemical synthesis
D000596:Amino Acids; D002234:Carbodiimides; D003512:Cyclohexanones; D004151:Dipeptides; D007202:Indicators and Reagents; D010455:Peptides; D004024:Dicyclohexylcarbodiimide; C036468:cyclohexanone; D014508:Urea