with complete retention of chirality as evidenced by NMR and HPLC analysis. Arginine LL-dipeptides 15a-d were synthesized by extension at the C-terminus of arginine in isolated yield of 66-80%, using benzotriazole activated arginine L-(omega)NO2-Arg-Bt, 13. Our methodology has also been used to synthesize the protected RGD peptide (Cbz(alpha)-L-(omega)NO2-Arg-Gly-L-Asp-(OH)2) 21.
LN(ω)-硝基精
氨酸和
L-精氨酸与N-(Cbz-α-
氨基酰基)
苯并三唑和N-Cbz-二肽基
苯并三唑偶联以提供精
氨酸LL-二肽9a-e,11a-d;LLL-三肽18a-c,20; 非对映异构体混合物(9b + 9b'),(9c + 9c'),(11b + 11b')和(18c + 18c')[括号内的化合物代表非对映异构体混合物或外消旋体;不带括号的化合物编号表示为非手性化合物或单一对映体,通过精
氨酸的N端延伸,分离出的收率为66-95%,并完全保留了手性,如NMR和HPLC分析所证明。使用
苯并三唑活化的精
氨酸L-(ω)
NO2-Arg-Bt,13在精
氨酸的C末端延伸,以66-80%的分离产率合成了精
氨酸LL-二肽15a-d。