Orthogonally Protected Cyclo-β-tetrapeptides as Solid-Supported Scaffolds for the Synthesis of Glycoclusters
作者:Pasi Virta、Marika Karskela、Harri Lönnberg
DOI:10.1021/jo052348o
日期:2006.3.1
4-methyltrityl (Mtt) and 1-methyl-1-phenylethyl protections (PhiPr) exposes the β-amino and carboxyl terminus, respectively, and on-resin cyclization then gives the desired orthogonally protected cyclo-β-tetrapeptides (1 and 2). The α-amino groups, bearing the Fmoc and Alloc protections and the azide mask, allow stepwise orthogonal derivatization of these solid-supported cyclo-β-tetrapeptide cores (1 and 2). This
两个新型肽支架,即。环[(Ñ α -alloc)DPR-β-ALA-(Ñ α -Fmoc)DPR-β丙氨酸](1)和环[(Ñ α -alloc)DPR-α叠氮基β-aminopropanoyl-(Ñ已经描述了由正交保护的2,3-二氨基丙酰基(Dpr)和β-丙氨酰基残基组成的α -Fmoc)Dpr-β-Ala](2)。主链酰胺接头衍生树脂上的Fmoc化学已用于链组装。选择性去除4-甲基三苯甲基(Mtt)和1-甲基-1-苯乙基保护基(PhiPr)分别暴露β-氨基和羧基末端,然后在树脂上环化,得到所需的正交保护的环β-四肽(1和2)。带有Fmoc和Alloc保护以及叠氮掩膜的α-氨基可逐步逐步衍生这些固体负载的环β-四肽核(1和2)。这已经通过各种糖单元[即附着物证明的,乙酰基或甲苯甲酰基保护的羧甲基α-。d -glycopyranosides(13 - 15)和甲基6- ø - (4-硝基苯氧基羰基)-α-