Di Gioia Maria Luisa, Leggio Antonella, Le Pera Adolfo, Liguori Angelo, Napoli Anna, Siciliano Carlo, Sindona Giovanni
Dipartimento di Scienze Farmaceutiche and Dipartimento di Chimica, Università degli Studi della Calabria, Via Ponte P. Bucci, Cubo 15/C, I-87036 Arcavacata di Rende (CS), Italy.
J Org Chem. 2003 Sep 19;68(19):7416-21. doi: 10.1021/jo034233v.
N-Nosyl-alpha-amino acid methyl esters are methylated quantitatively with diazomethane. After proper deprotection of the amino function by treatment with the reagent system mercaptoacetic acid/sodium methoxide, the obtained N-methyl amino acid methyl esters are coupled with N-Fmoc amino acid chlorides to afford the corresponding dipeptides. The obtained products do not show any detectable extent of racemization by (1)H NMR and HPLC.
N-亚硝基-α-氨基酸甲酯与重氮甲烷进行定量甲基化反应。在用巯基乙酸/甲醇钠试剂体系对氨基进行适当的脱保护后,所得的N-甲基氨基酸甲酯与N-Fmoc氨基酸氯化物偶联,得到相应的二肽。通过¹H NMR和HPLC分析,所得产物未显示出任何可检测到的消旋程度。