Synthetic studies of the spirocyclic cyclohexene part of versipelostatin, a novel GRP78/Bip molecular chaperone downregulator
作者:Shu Sasaki、Suguru Samejima、Tomoki Uruga、Kai Anzai、Natsumi Nishi、Eriko Kawakita、Ken-ichi Takao、Kin-ichi Tadano
DOI:10.1038/ja.2012.124
日期:2013.3
The spirocyclic part consisting of an α-acylated tetronic acid and a multisubstituted cyclohexene embedded in versipelostatin, a novel GRP78/Bip molecular chaperone downregulator, has been synthesized in enantiomerically pure form. The asymmetric synthesis of the targeted spiro[4.5]-1-oxa-7-decen-2,4-dione derivative was characterized by (1) stereoselective allylation at the α-carbon of methylmalonate diester, in which one carboxylic acid was esterified with a D-glucose-derived chiral template, (2) construction of the tetrasubstituted cyclohexenone substructure by high-yielding ring-closing metathesis and (3) stereoselective construction of the spirocyclic tetronic acid part starting from the cyclohexenone obtained as the ring-closing metathesis product.
含有α-酰基的丁二酸酐和多取代环己烯嵌入的新型GRP78/Bip分子伴侣下调剂versipelostatin中的螺环部分,已以纯手性形式合成。目标螺[4.5]-1-氧杂-7-癸烯-2,4-二酮衍生物的不对称合成具有以下特点:(1)在甲基丙二酸二酯的α-碳上进行立体选择性烯丙基化,其中一个羧酸与D-葡萄糖衍生的手性模板酯化;(2)通过高产率的环合复分解构建四取代环己烯酮子结构;(3)从作为环合复分解产物得到的环己烯酮开始,进行立体选择性构建螺环丁二酸酐部分。