Synthesis of des-n-tetramethyltriostin a from C-terminal Z-d-serine tetra-and octadepsipeptide intermediates
作者:Madhup K. Dhaon、Joseph H. Gardner、Richard K. Olsen
DOI:10.1016/0040-4020(82)85045-x
日期:1982.1
derived from 6, furnished linear octadepsipeptide 9, which upon cyclization and disulfide formation gave the bicyclic octadepsipeptide 11, a known synthetic precursor to 1. The degree of racemization incurred in the alanine and valine residues of selected depsipeptides was measured and the results compared with those obtained in previous studies. It was concluded that alanine, perhaps because of sequence
Des-N-四甲基triostin A(1),一种已知的DNA嵌入剂,是由在C端位置具有Z -d-丝氨酸的四肽和八肽中间体合成的。因此,该方法允许片段偶联和环化反应,导致标题化合物的合成发生,而在C-末端氨基酸没有外消旋化。与将Boc-VAL-OH的酯化p的-bromophenacyl酯ž -d丝氨酸提供didepsipeptide Ž -d-SER(BOC-VAL)-OBpa(4)。逐步添加必需氨基酸可提供四肽Z -d-Ser [Boc-Ala-Cys(Acm)-Val] -OBpa(6)。分别衍生自6的C和N去保护的四肽肽7和8的片段偶联提供了线性八肽9,其在环化和二硫键形成后产生了双环八肽11,即1的已知合成前体。测量所选二肽中丙氨酸和缬氨酸残基的消旋程度,并将结果与以前的研究结果进行比较。结论是,丙氨酸可能是由于序列效应,在四肽6和八肽9的水解过程中会发生一定程度的消旋(4-10%)。