Parallel Synthesis of Novel Heteroaromatic Acromelic Acid Analogues from Kainic Acid
作者:Jack E. Baldwin、Andrew M. Fryer、Gareth J. Pritchard
DOI:10.1021/jo000846l
日期:2001.4.1
A range of new C-4 heteroaromatic acromelic acid analogues has been synthesized in a parallel fashion from (-)-alpha-kainic acid 1. Protection of the amine and carboxylate groups of 1 followed by ozonolysis gave methyl ketone 8. A silyl enol ether 9, generated regiospecifically from the methyl ketone 8 using "kinetic" conditions, was brominated in situ with phenyltrimethylammonium perbromide to give
已由(-)-α-海藻酸1以平行方式合成了一系列新的C-4杂芳族丙烯醛酸类似物。保护1的胺基和羧酸基,然后进行臭氧分解,得到甲基酮8。甲硅烷基烯醇醚如图9所示,在“动力学”条件下由甲基酮8区域专一性生成的产物,与过氧化苯三甲基铵原位溴化,得到关键的α-溴代酮10。然后进行溴代酮10与硫酰胺和硫脲的平行环化反应。将产生的芳族杂环衍生物11a-d和19脱保护,以优异的产率得到新的类胡萝卜素氨基酸6a-d和25。化合物6a和6c显示出与海藻酸酯受体的强结合。还简要研究了10与替代缩合剂的反应。