Construction of Fused Cyclooctanoid Ring Systems via Seven-Membered Ring Carbonyl Ylides
作者:Sengodagounder Muthusamy、Srinivasarao Arulananda Babu、Chidambaram Gunanathan、Eringathodi Suresh、Parthasarathi Dastidar
DOI:10.1246/bcsj.75.801
日期:2002.4
A series of α-diazo carbonyl compounds tethered to cyclopentanone/cyclohexanone/1-tetralone units have been synthesized using a diazomethane solution to construct various fused cyclooctane ring systems via rhodium-generated carbonyl ylides. The reaction of rhodium(II) acetate dimer with various α-diazo carbonyl compounds generated transient cyclic seven-membered ring carbonyl ylides, which underwent facile 1,3-dipolar cycloadditions with dipolarophiles, like N-phenylmaleimide, p-benzoquinone, and DMAD to furnish a variety of fused epoxy-bridged cyclooctane ring systems in a tandem manner. Interestingly, an oxepine ring system was generated via an intramolecular proton transfer of a seven-membered ring carbonyl ylide. A tri-oxa polycyclic compound was obtained in the case of p-benzoquinone as dipolarophile. A single-crystal X-ray analysis of a fused cyclootanoid derivative is reported to decisively establish the structure and stereochemistry of the fused epoxy-bridged cyclooctane ring systems; a further analysis revealed the existence of a unique intermolecular C–H···π interaction motif in the solid-state architecture.
一系列连接到环戊酮/环己酮/1-四氢萘酮单元的α-重氮羰基化合物通过使用重氮甲烷溶液,通过铑产生的羰基叶立德构建了各种融合的环辛烷环体系。铑(II)醋酸二聚体与各种α-重氮羰基化合物的反应生成了瞬态的七元环羰基叶立德,这些叶立德与亲二极体如N-苯基马来酰亚胺、对苯醌和DMAD进行了方便的1,3-偶极环加成反应,以串联方式提供了多种融合的环氧桥接环辛烷环体系。有趣的是,通过七元环羰基叶立德的分子内质子转移生成了一个oxepine环体系。当对苯醌作为亲二极体时,得到了一个三氧杂多环化合物。报道了对融合环辛烷类衍生物的单晶X射线分析,以明确确定融合环氧桥接环辛烷环体系的结构和立体化学;进一步分析揭示了固态结构中存在的独特分子间C-H···π相互作用模式。