Functionalised 2,3-dimethyl-3-aminotetrahydrofuran-4-one and N-(3-oxo-hexahydrocyclopenta[b]furan-3a-yl)acylamide based scaffolds: synthesis and cysteinyl proteinase inhibition
作者:John Watts、Alex Benn、Nick Flinn、Tracy Monk、Manoj Ramjee、Peter Ray、Yikang Wang、Martin Quibell
DOI:10.1016/j.bmc.2004.03.042
日期:2004.6
Application of standard methods for the preparation of amino acid alpha-diazomethylketones, through treatment of the mixed anhydride or pre-formed acyl fluorides of intermediates 12-14 with diazomethane, proved troublesome giving complex mixtures. However, the desired alpha-diazomethylketones were isolated and following a lithium chloride/acetic acid promoted insertion reaction provided scaffolds 6-8. Elaboration
立体选择性合成官能化的(2R,3R)-2,3-二甲基-3-酰胺基四氢呋喃-4-酮,其(2S,3R)-受体和(3aR,6aR)-N-(3-氧代-六氢环戊五烯[b]使用Fmoc保护的支架6-8以固相组合策略开发了呋喃-3a-基)酰基酰胺半胱氨酸蛋白酶抑制剂。在这些支架中,将烷基取代基α引入酮可为原本在结构上不稳定的分子提供手性稳定性。制备支架6-8时需要适当保护的α-重氮甲基酮中间体9-11的立体选择性合成,该中间体9-11由适当保护的α-甲基苏氨酸(2R,3R)-12,(2R,3S)-13和受保护的类似物(1R, 2R)-1-氨基-2-羟基环戊烷羧酸14.标准方法在制备氨基酸α-重氮甲基酮中的应用,通过用重氮甲烷处理中间体12-14的混合酸酐或预先形成的酰基氟,证明很麻烦,无法得到复杂的混合物。然而,分离了所需的α-重氮甲基酮,并在氯化锂/乙酸促进的插入反应之后提供了支架6-8。在固相上精制