Construction of the Septahydroxylated ABC-Ring System of Dihydro-α-Agarofurans: Application of 6-exo-dig Radical Cyclization
Construction of the Septahydroxylated ABC-Ring System of Dihydro-α-Agarofurans: Application of 6-exo-dig Radical Cyclization
复制标题
二氢-α-沉香呋喃七羟基化 ABC 环体系的构建：6-exo-dig 自由基环化的应用
DOI：
10.1039/c7cc00507e
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
M. Inoue
中科院分区：
文献类型：
--
作者：
H. Fujisawa;T. Ishiyama;D. Urabe;M. Inoue
建立了七羟基化ABC环系二氢-β-沉香呋喃的合成路线。B-环通过3-羟基-2-吡喃酮和D-甘油醛衍生的亲二烯体之间的碱促进的非对映选择性Diels-Alder反应形成，而C-环通过PhSeCl介导的醚化环化。剩余的A环通过6-exo-dig自由基反应构建。选择性转化产生了ABC环系统1与9个连续的立体中心。由此获得的1对应于二氢-β-沉香呋喃的密集氧化核心结构的对映异构体。
A synthetic route to the septahydroxylated ABC-ring system of dihydro-β-agarofurans was established. The B-ring was formed by a base-promoted diastereoselective Diels–Alder reaction between 3-hydroxy-2-pyrone and a D-glyceraldehyde-derived dienophile, while the C-ring was cyclized by PhSeCl-mediated etherification. The remaining A-ring was constructed via a 6-exo-dig radical reaction. Selective transformations gave rise to the ABC-ring system 1 with nine contiguous stereocenters. The thus obtained 1 corresponded to the enantiomer of the densely oxygenated core structure of dihydro-β-agarofurans.