Anomeric α-azido acid (2-azido-2-deoxy-hept-2-ulopyranosonic acid) derivatives en route to peptides incorporating sugar amino acids
作者:Katalin Czifrák、Péter Szilágyi、László Somsák
DOI:10.1016/j.tetasy.2004.11.064
日期:2005.1
(2-bromo-2-deoxy-α-d-hept-2-ulopyranosonic acid derivatives), while a glycinamide was split along the –H2C–NH– bond. Anomeric bromides of the glycinamides were obtained by N-acylation of a glycine ester with the pentachlorophenyl 2-bromo-2-deoxy-ulosonates. In this reaction the axial anomeric bromide proved stable. Sodium azide in DMSO or DMF was used for the substitution of the anomeric bromides. These reactions proceeded
Per- ø -acylated的2,6-脱水aldoheptonic酸D-甘油基-D-庚和D-甘油基-1-甘露配置由相应aldonamides的亚硝化过程得到转化入甲基- ,叔丁基- ,2,按照标准程序,得到2,2-三氯乙基和五氯苯基酯,酰氯和甘氨酰胺。在Bz 2 O 2或AIBN或CH 2中的Na 2 S 2 O 4 –KBrO 3存在下,通过溴在沸腾的CHCl 3中在光照下进行溴化,或在沸腾的CCl 4中在NBS中进行自由基介导的溴化。在室温下使用2 Cl 2-水两相溶剂混合物,得到上述酯和酰氯的2-溴化物的轴向异构体(2-溴-2-脱氧-α-d-庚-2--2-吡喃磺酸衍生物),而甘氨酰胺沿–H 2 C–NH–键分裂。通过将甘氨酸酯与五氯苯基2-溴-2-脱氧-磺基磺酸酯进行N-酰化,获得甘氨酰胺的端基溴化物。在该反应中,轴向异头溴化物证明是稳定的。使用DMSO或DMF中的叠氮化钠替代异