N-Carboxy α-dehydroamino acid anhydride, derived from N-benzyloxycarbonyl α-dehydroamino acid (DHA) and thionyl chloride, was found to be very useful for the synthesis of N-free DHA ester by alcoholysis and N-acetyl dehydrodipeptide ester by coupling was α-amino acid ester.
N-羧基 α-脱氨基酸酸酐是由 N-苄氧羰基 α-脱氨基酸(DHA)和氯化亚硫酰制得的,发现它在通过醇解合成无氮 DHA 酯和通过偶联合成 N-乙酰脱二肽酯时非常有用。
Dehydrooligopeptides. I. The Facile Coupling of α-Amino Acids with α-Dehydroamino Acids to Dehydrodipeptides
N-Cbz- or N-Tos-α-dehydroamino acid (DHA) and its ester were prepared by the condensation of 2-oxo carboxylic acid or ester with benzyl carbamate or p-toluenesulfonamide. Subsequently, the N-protected DHA and its N-free ester thus obtained were coupled with several L-α-amino acid esters and N-protected (Boc or Cbz)-L-α-amino acid respectively by the usual peptide synthetic methods to give a number
N-Cbz-或N-Tos-α-脱氢氨基酸(DHA)及其酯是通过2-氧代羧酸或酯与氨基甲酸苄酯或对甲苯磺酰胺缩合制备的。随后,将由此获得的 N-保护的 DHA 及其无 N-酯分别与几种 L-α-氨基酸酯和 N-保护的(Boc 或 Cbz)-L-α-氨基酸通过通常的肽合成方法偶联到给出许多不同类型的脱氢二肽。获得的所有新 DHA 和脱氢二肽的构型均显示为 (Z)-几何。
α,β-Unsaturated Carboxylic Acid Derivatives. XXI A Novel Synthesis of α-Dehydroamino Acid Derivatives by the Arbusov Reaction of α-Phosphoranylideneamino-2-alkenoates
The reaction of ethyl 2-azido-2-alkenoate with organic tervalent phosphorus reagent gave the corresponding 2-phosphoranylideneamino derivative as an stable intermediate. This transformed gradually at room temperature, or immediately on a silica-gel column to give the corresponding 2-phosphinylamino derivative in a good yield. The Arbusov reaction of the intermediate which occurred during the transformation
dehydrodipeptides with a hydroxyl group, obtained by the coupling of 1 with a serine or threonine ester, and that of N-protected serine or threonine with 2, followed by mesylation and subsequent base-catalyzedβ-elimination gave a number of 7 substances in good yields. The configurational structures of 7 obtained by both direct condensation and elimination were found to have (Z,Z)-geometry.